Jomon Six-Pillar Building

Sannai Maruyama Site
Aomori, Japan

This enigmatic structure dates to around 2600 BC. The building seen here is, of course, a recreation based on a few postholes stuck into the ground. There are several more like it, scattered around the compound. Its most likely interpretation is a watchtower, but that's not the only possible explanation. Considering the assemblage as a whole - most of them face the same direction - and the multiple floors of the building - it could also be a palace or ritual building.