Blog Sites Aligned to the Sun

Using SunCalc to Check Solar Alignments at Ancient Sites

With all the interest surrounding ancient sacred sites aligned to the sun and exploring new local ones, I thought to highlight a quick tool called SunCalc for looking up alignments at solstices and equinoxes.

angkor wat equinox alignment

The equinox alignment at Angkor Wat in Cambodia, as shown on SunCalc (indicated by the yellow line). Image created with SunCalc, using imagery © 2017 GeoEye, map data © 2017 Google.

Angkor Wat Spring Equinox Alignment

A real-life example of the sun crowning the pinnacle of the central tower of Angkor Wat at the spring equinox. Photo by take… (CC BY 2.0), via Flickr.

There is a myriad of ancient sacred sites around the world and more are being discovered regularly, yet not all of these sites have been studied from the perspective of archeoastronomy — which can sometimes make it difficult to figure out if a site has any connection to solstices and equinoxes. One quick way anyone can do an initial check on solar alignments at a specific site on their own is to run it through and see what comes up — which can be helpful to see before visiting a new sacred site, for example, to understand where its solstice or equinox alignments can be best observed.

SunCalc uses Google Maps to map out the sun’s rising and setting points on specified days throughout the year. Sites can be looked up simply by searching for their name or the general location and then zooming in and moving the marker onto the spot of interest, or by looking up specific GPS coordinates.1 This provides a basis upon which hypotheses about solar alignments can be made and further studied and/or observed in person.

Note: keep in mind that solstice and equinox angles shift over time due to variations in the earth’s tilt due to the precession of the equinoxes. So when looking at very ancient sites the alignment angles currently shown can be slightly off.

An Example of How SunCalc Can Be a Useful Tool for Exploring Ancient Sites

Some time ago my husband and I visited an ancient complex called Ratu Boko,2 situated on a mountain peak in Java, Indonesia. This complex featured a lovely gate that was a key attraction, and which we were told was commonly used as a backdrop to watch beautiful sunsets by visitors. This made us wonder if perhaps this site was aligned to solstices or equinoxes.

ratu boko equinox

My husband, Jordan, walking towards the sun gate. The sun sets on the other side of the gate.

As it’s a lesser known site, we could not find any information discussing its solar alignments. While there, we could however tell that some of the structures at the complex were aligned in a particular orientation. Given the gate’s focus on sunsets, we guessed that if the site is indeed aligned to solstices or equinoxes, it’s more likely to be related to the autumn equinox, or possibly the summer solstice, since celebrations of these events typically involve watching the sunset.3

At the time we weren’t aware of the existence of SunCalc yet, but had we known about it in advance it would have saved us a lot of guesswork. After our visit we were able to search for Ratu Boko on this solar calculator, which showed that the sun gate aligns to the equinox sunset.

This alignment can be seen on the map below (the pointer is where the gate is, and the red line shows the sunset alignment):

ratu boko equinox alignment

SunCalc shows an equinox alignments at the sun gate in Ratu Boko in Java, Indonesia. Image created with SunCalc , using imagery © 2017 DigitalGlobe, map data © 2017 Google.

Using SunCalc for Creating a Sacred Site

This tool can also be useful in creating sacred sites and has been previously recommended on the Guide to Creating a Sacred Site Aligned to the Sun. It can be handy, for example, for having a visual reference and coordinates of sunrises and sunsets from the chosen location for the site.

  1. Note: it can be easier to understand the sunrise and sunset alignments on if the legend on the right side of the screen is changed to the “more detailed” version. 

  2. More information about this site will be available in a separate future article. 

  3. Further information about solstice and equinox celebrations can be found in:
    Belsebuub and Angela Pritchard, The Path of the Spiritual Sun: Celebrating the Solstices and Equinoxes (Mystical Life Publications, revised second edition, July 2017).  

About the author

Jenny Resnick

Jenny Resnick is a researcher and practitioner of the ancient religion of the sun and the Managing Editor for The Spiritual Sun, where she also researches and writes about ancient sacred sites; spiritual texts and practices; the latest discoveries in archeology, archeoastronomy, and related sciences; as well as the exploration of various facets of the lost civilization of the sun.


  • Thanks Jenny for the post. I have just tried Suncalc and it does a very neat plot of sunrise and sunset superimposed on a Google map of the place. It’s nice that it’s so simple to use.

    I used Stellarium before, which is a bit more in-depth program that basically allows you to see the actual movement of objects (Sun, moon, stars) from any location on Earth and at any date (past or future).

    After using software for archaeoastronomy research I have some words of caution that basically limit how much you can do with these programs. First of all these programs typically do not take into account the slope of the land. So, if you are on the side of a high mountain, or if the ground slopes slightly then the angles will be slightly different.

    Secondly, and most importantly, they do not give you a feel for the land. Some sacred sites I’ve been to incorporate the land’s topography into their alignments. They often use mountain peaks, valleys, and other unique features. These topographical alignments are impossible to see unless you are present on the site in person, and studying it (often using software that you mentioned).

    • Thanks for sharing these tips and I definitely agree. I felt that so far personally this tool has been most helpful after I had already visited a site and had a good idea of the situation of the different elements there. Without having been there and not knowing these places would have made alignment tracking in my case very difficult if not impossible (beyond telling general orientation of sunrise in relation to the area — which still would have been helpful to know beforehand). Having a tool like this to confirm the alignments once you know where to look is very helpful though.

      In some cases you can tell an alignment without being there as well — I think it depends on how clear the structure of the site is and its surroundings. For example, if you look up Newgrange you can see clearly how the summer solstice alignment passes over the main entrance and the winter solstice alignment passes over the “window” in the mound. These are the only two external openings, so the alignment seen is quite clear. Likewise, if you look up the temple of Apollo in Greece, if you place the cursor over the entrance steps you can see something close to a summer solstice sunrise alignment (which I later confirmed as a hypothesis via another source). These are very large and their main features are well-known / clear or can be investigated from afar via many photos and information available online and in books, etc.

      • I agree that you can do quite a bit without actually visiting the site. I have also wondered about the value of doing the research yourself (on the ground). It is not complicated for the average person to do it well, but it does take more time.

  • This is a great, easy to use and fun resource. I was pretty sure my spot would be ok for the equinoxes (it’s near the southern most tip of mainland Australia), but it was very cool to visualize it with this tool.

  • SunCalc is a great, easy to use, free tool. I first stumbled across it years back (the online desktop version), to work out if locations would be a good place to observe the solstice or equinox sunrise/sunset.

    You can just set the date and drag and drop the marker around to different points on the map to see where the sunrise will be from specific locations on that day.

    Of course, you still need to go to the location to setup more more precise alignments, as it doesn’t take into account the lay of the land and topography (the angle the sun appears will be slightly different if there are hills or trees which obstruct view a bit, making the visible horizon on the ground higher). But it certainly takes the guess work out when trying to pick a good place to observe the solstice or equinox to start with.

    It never occurred to me to use it in this way at the time, but it actually provides a really good way just to get an initial idea of whether a little-known site has alignments to the sun, and warrants a visit or further study. A very handy tool.

  • I checked this app first when you wrote about the guide to creating a sacred site and I found it very usefull indeed. It won’t give detailed information specially for not well known places but is definately accurate where to look for such places, for example creating a sacred site from scratch.

  • That is super cool! What a useful program. When I read the title of this post I was expecting a phone app for when you’re already on the ground somewhere, but this is very handy for researching ahead of time the different locations or sites that you’re curious about.

    I’ve wondered about some sites that I’ve come across online, but if there’s not much information already published about a place then it’s hard to know if there is even the possibility of alignments. Happy to find out that there are some options for digging a little deeper. Thanks for sharing.

  • Seems like a excellent tool for checking the alinements, really helps to take the guessing game out of it thanks

  • Thanks Jenny. I hadn’t stumbled across Suncalc yet, but it seems like a helpful tool A few years ago I found a tool for Photographers to plot sunrise/sunset/s times and horizon locations for getting the best shots and I used it prior to a trip in Mexico to do some research on sites there. At a glance they look quite similar but Photographers Ephemeris also includes moon rise & set and some interactive graphs. It would be pretty awesome to see some tool like this also be able to report celestial bodies, like planets or constellations.,-88.568674&center=20.6831,-88.5687&dt=20170820123700-0500&z=18&spn=0.00,0.01

    • Cool, thanks for sharing that Andrew. It’s amazing these things exist now – makes things a lot easier doesn’t it!

      Yes, I was wondering about a star/sky plotter as well. I saw one being used in a documentary to plot the Pyramids at Giza and Angkor Wat to different constellations in the sky at different periods in history so I know such a thing exists, but as to whether it’s available to the public or just something the researchers created for their own use, I’m not sure.

    • Thanks for sharing, Andrew — looks like another neat app.

      For connections with celestial bodies, constellations, past alignments, etc. there’s something people use called Starry Night. Though it’s not a free app, good to be aware of it for those that want to dig deeper at any point.

      • Some free software I used to use a lot when stargazing with my telescope was a program called Stellarium. It was pretty good and could do all the things like selecting different locations, times of the day, dislay sunrise coordinates etc. And see what the skies looked like at that time. It could also go back in time like Jordan mentioned. Interesting to see what the skies looked like on the night/morning you were born or at big events in the past.
        (Although to do it in a way where you can be absolutely sure of the accurateness of the skies thousands of years ago for example might require an expert, because there’s there’s also different calendars and ways of calculating and other factors.)

        I still use it and I think the program is still available although I’m not sure if it’s still updated as frequently as it was back then.

        I learned quite a bit from using it actually.

  • Thanks for this article Jenny.
    I’ve recently discovered of the existence of several sites near me and suncalc helps to determine if they have solar alignments. Unfortunately, some of these areas are remote and the satellite images are too low quality to check easily — but it’s excellent opportunity for a road trip!

    • Yes I wondered the same Craig. Many sites may be too unknown, and therefore their ancient or significant past may be unrecognised, let alone captured on satellite, which makes the research into their alignments very important in uncovering their intentful purpose. Having that link to the religion of the sun really gives a new and unified meaning to so many sacred places in the world.

      The team at Modern Explorers who have produced many videos documenting ancient sites, go out to search dozens of unknown but incredibly intriguing and seemingly intentfully designed stone structures, pyramids, sites etc.. around the world, but then they ask the obvious ‘why’. At this I always wonder if it were just possible to have some kind of tool on the grounds to establish if there were any solar alignments. This in my opinion would dramatically confirm the incredible reality of the solar religion, and how significant and far reaching was the spirituality of the sun, even in remote places.

      Christos and I tried to pin point any significant alignment at Phaistos Palace in Crete, an island in Greece that is full of Minoan history. As we were walking around the ruins it was very hard to tell or observe any points of interest that would be aligned.

      Then at one point I overheard a tour guide speaking of a sacred place looked after by priestesses that had two very holy pillars. It was a small space, but it also had a window. Trying our best, we went over to see if we could use one of the sunrise apps in Christos’ phone to see where the sunrise would be, and yes their was an alignment – but the technology may not be the most accurate. I am curious to use the suncalc on this one to verify if there was really something there.. Actually, there are a few other places that can be much more easily identified for their alignments using suncalc… in fact many people can become independent researchers in this aspect and upload their findings on a variety of unlisted, unrecognised sites and their link to the religion of the sun. For example allegedly the Great Wall of China has alignments, but being such a vast site, I don’t know where the precise alignment is visually. Would love to check it out and confirm.

      Thanks very much for sharing Jenny! Hopefully in the future more and better apps could be developed in tracking alignments, however this certainly is leading the way for new research to be gathered where previously the territory seemed ordained just for the professionals. Thanks for the tips!

      • No worries, Olga. It’s definitely a handy tool. There is a good app for more detailed research, past alignments, constellations, etc. I mentioned it in my reply to Andrew above, but it’s not free as it’s more of a professional software. For simple research though, SunCalc (or the one Andrew mentioned above as well) is a great free tool.

        I think to properly check alignments in most cases it is best to visit the site, because without the understanding of how things are situated it can be hard to figure out where to check for alignments exactly.

        • There’s a few desktop apps you can use. I use stellarium, a free tool:
          Set your gps position, and you can wind forward & backward in time.
          It’s a strange program, but once you get around that, it’s quite useful. Perhaps others here might find it useful too.

          • That’s the one I’ve also made use of Craig. I think that even though mobile smartphones have their good sides such as they can be more easily taken on location and have internal compass and gps etc. I think they sometimes lack the precision and detailed information that desktop programs provide.

            I personally haven’t looked into it too much but perhaps there are also plug ins that can be added to work together with Stellarium or Google Earth. In order to overlay images over the landscape and such.

      • I just checked in SunCalc, and Phaistos Minoan Palace in Crete has an area where it seems a distinct Equinox (March and September) sunrise/sunset alignment can be observed through a long corridor space.

        Another building more south, seems like its walls are aligned to the summer solstice sunset.

        • Very cool 🙂

          Here’s an abstract that seems to confirm your observation.

          This is another valuable aspect I see in this tool — it can give you pointers for exploring lesser known sites, and a way to discover new ones. There are so many known sites out there, but I find available information about ancient sites generally centers on a small percentage of them. It’s nice to be able to step outside of that already familiar zone and see what else is out there 🙂

  • That’s a fantastic tool Jenny, thanks for sharing! It’s true there are so many ancient sites that simply haven’t had someone look at them to take these solar measurements, and so many more to discover than can be physically visited. This will help an enormous amount reveal what’s encoded into a site.

  • Thanks for sharing this – it is a very remarkable tool.

    I actually found out about it only recently myself. The other day I was researching a particular site, without a knowledge of any alignments it had, and decided to plug it into SunCalc. I immediately saw that it aligned perfectly to the summer solstice sunrise.

    It was very striking to see it — somehow it helped make it “real” in a way that is harder to convey through just hearing the alignment described in writing. It also felt quite exciting to see that this ancient site did in fact line up to a solar event, just as we might have predicted if it had been connected to the Religion of the Sun. I later found the alignment mentioned in a book, which validated what I had seen.

    I spent some time checking other sites I was aware had alignments, just to see them for myself (at least digitally!). I also checked out some other sites that I was not aware of having any alignments. In some cases I could not detect anything, but in a few others I was able to see clear alignments to solstice events – perhaps these alignments had not been identified by anyone before. It makes me grateful there is such an easy way to do this sort of research now.

    Using the tool also helped give me a better understanding of how the sun moves throughout the year, as you can easily change dates and observe the effects on the sunrise and sunset.

    All in all it seems like an exciting tool that has many applications — for research of ancient sites, creating modern ones, and just exploring the path of the sun in specific places.

  • Thanks for sharing Jenny. My brother lives in Bali, next time I visit him I’ll try to locate a solstice or equinox location.

    • Hey John,

      That’s a neat idea. We visited Bali as well and went to the main island temple (Besakih) and some of the ancient sites there. On the island the particular custom in general is to orientate temples and dwellings north-east (east to the sunrise, and north to the sacred part of the island — the mountains, which are considered the dwelling place of the gods). So you’ll find that alignment in some of the temples there, instead of solstice and equinox ones. Many temples were also rebuilt many times due to earthquakes and volcanic eruptions, and it’s possible they may have lost their original alignments in the process.

      However, we did visit some really interesting ancient sites there, particularly various caves and rock structures. I found through SunCalc that one of these sites aligns perfectly to the spring equinox sunrise in several locations — it’s called Gunung Kawi, and was one of my favorite places to visit in Bali. It’s just really beautiful and it’s incredible to see the ancient solid rock masonry. I”ll try to write more about it in the future. Just a note: be prepared for lots of steps at this place 🙂

      Another interesting cave we visited was Goa Gajah, and SunCalc seems to show that there is a summer solstice sunrise alignment behind the main cave and in alignment with the pools in front of it, though I’m not really sure how this would be observed in person. It’s worth visiting this place as it’s also quite beautiful (especially the inner forest ancient structures), and it’s quite close to Gunung Kawi so you can cover both in a day.

      If you find any more, would love to hear about them!

      • Thanks Jenny, my nephew Chris was recently in Bali and as you’ve mentioned he was told that many temples had been rebuilt. I’m sure that the SunCalc would have come in very handy for him.

  • Thanks Jenny, that’s useful tool to know about. And like you say it seems like it can be a useful addition when planning visits and such.

    I even found it interesting for just seeing where the sun rises and sets where I live. As well as seeing the exact times sunrise, sunset and solar noon happens for the places I chose to look at it. I know there’s some websites as well where you can get very exact coordinates, which is also useful in its own way, but then to translate that to real life you’d need a compass.

    I noticed when looking at some sites that were more remote that the resolution of the google image isn’t always great, this limits what can be made out of course. But I think this app is still very useful, especially for quick checks, which is very easy through suncalc it seems.

    • Yes, it has its limitations (such as for example being limited by available imagery and mapping for more obscure places, or having to know the place enough to know which specific spot to check for alignments, which isn’t always obvious from a map), but I’m still super grateful to whoever put it together — it can cut out a lot of guesswork and give fast and very simple overviews of potential alignments. It came in particularly handy for me for checking up on lesser known sites I’ve already visited in person, as I then knew their layout really well and therefore was able to get sufficient info to check for alignments at certain spots. It’s definitely a nice one to have in your tool belt 🙂

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