Deep within the jungle on the Samoan island of Savai’i lies a big heap of stones half the size of a football field. This is the Pulemelei Mound — also known as the Tia Seu Ancient Mount — and nobody really knows when it was erected, or why it is there.

With a base measuring 65 meters by 60 meters (213 feet by 197 feet), Pulemelei Mound consists of a foundational platform of volcanic rock supporting multiple layers of natural basalt stone, piled on top to a height of 12 meters (23 feet). The structure is pyramidal with flat top. Several purposes have been proposed for this structure, including use in religious ceremonies, as a lookout platform, or as a burial monument. It most likely served multiple functions, but in truth the reason for its construction and the role that it played remain unknown.

Pulemelei Mount was most likely built sometime between 1100 and 1400 CE and remained active until 1700-1800, after which time it fell into disuse and was left to be reclaimed by the jungle. Although it is occasionally cleared of vegetation to reveal the details of its stone construction, the easily concealed structure is very quickly overgrown by the lush forest surrounding it once again, adding an additional degree of difficulty to the already tricky task of finding it.

The site is located in Letolo Plantation, a short walk away from the road. The way is unmarked and can take some trial-and-error to find, and seeing a pyramid needs a bit of imagination if it has not been cleared up recently. Once there, however, you can see the ocean from the top, and the views are magnificent.