Why are there keyholes around Japan

Beyond the practical answer, to lock things up, what is the real reason for the keyhole shapes in Japan?

Have you ever caught yourself lost in a daydream, scrolling through Google Maps and longing for a Japanese adventure? Maybe you blink twice, wondering if your imagination is playing tricks after so many hours yearning for Tokyo. Then, out of nowhere, a perfect keyhole shape appears on the map. Is it a wink to Kingdom Hearts? Japan does love to sprinkle in surprises and easter eggs to many a franchise. In my own prefecture, we even have a train and a bus decked out with Romancing Saga characters. Japan itself feels like a giant keyhole to another world. It often feels enchanting, miles apart from the countries in the West.

The phenonium explodes when you start to scroll over Kansai, and you see big and small keyhole shapes dotted around the map, sometimes next to each other and sometimes alone. So, what is it? Is it a Kingdom Hearts Easter egg that has been taken too far? Is it a gateway to another world, after all? People often speak of being spirited away, a concept frequently found in Japanese folklore and anime. In fact, anime would have you believing that if someone isn’t isekaid every week, are you even in Japan?

Well, the answer is no to all the above. I hope I haven’t set your expectations soaring too high, because while the truth is fascinating, it might not be quite as magical as my buildup.

These keyhole shapes are Kofun, ancient Japanese burial mounds; think of them as Japan’s answer to the pyramids. They date back to the 3rd century and were in use until around the 7th century. The largest of these keyholes lie in Osaka, and many have earned UNESCO recognition. What I find delightful is that, unlike European churches that all face a set direction, these Kofun point every which way, creating a patchwork of keyholes all facing different directions.

I was lucky enough to catch a special Haniwa exhibit at the Kyushu Museum, where terracotta grave offerings called haniwa were on display. This was my first real encounter with Kofun culture. Much like the treasures buried with pharaohs in Egypt, haniwa are terracotta figures of all shapes and sizes, placed in ancient tombs. The most elaborate ones were reserved for people of high status.

The burial chamber is always located in the circular section of the keyhole; the more ornate ones have been known to incorporate paintings and more elaborate grave goods. Some of these paintings have been designated as national treasures. And the larger Haniwa were often placed on the perimeter of these burials to protect the burial. There are a jaw-dropping 161,560 Kofun in Japan alone. The largest amount is in Hyogo.

The larger Kofun now can fool you into thinking that you are looking at a lake with an overgrown island in the middle. At first, Kofun were small, and earlier burials contained copper items, swords, and clay goods. Kofun were also not reserved for just men; there are a few that belong to women of status. During the mid-Kofun period, buildings hit their height; this is also when the largest Kofun was built.

You can visit many kofun in Japan and explore the insides of them to understand how they are constructed. I have yet to see one up close in person, but I have seen a few from afar when I was in Nara and Osaka. There are many more different-shaped Kofun in Japan, but the keyholes by far capture the imagination. For many, the keyhole is associated with doors and portals. We see the keyhole as the barrier to another place. It wasn’t until I was scrolling the map, trying to locate somewhere to eat, that I saw my first keyhole on the map. It led down a rabbit hole lasting nearly two hours of exploring the Kansai region and having my mind blown by how many I saw.

I was hooked and delved deeper into what they were and had my mind blown by their number.  I found it a fascinating read, so I decided to share it with you also. Maybe next time, when you are scrolling through locations in Japan for your dream trip, you can take some time to see if you can spot any keyholes hidden in the map.