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....