EASTER ISLAND — This remote speck in the South Pacific is famous for its colossal stone statues, nearly 1,000 of them towering over the landscape like guardians.

Who built them? How did they get there? And who fitted some of them with giant red stone hats weighing up to 12 tons each?

When I was a kid, a huge nonfiction best seller by Erich von Däniken called “Chariots of the Gods” argued that they were evidence that U.F.O.s had visited Earth. Von Däniken, whose nonfiction and fiction books have sold a staggering 63 million copies worldwide, argued that only space aliens could have carved, transported and erected these monuments.

The puzzle arises because when Jacob Roggeveen discovered the island (on Easter Day, 1722, hence the name), it was a wasteland with no trees and a small, starving population. The Polynesian inhabitants had only small and leaky canoes, so it was unclear how they had ever reached the island, let alone built such colossal figures.