Archaeological sites whose construction, purpose, or builders remain debated.
A hillside maze of stone chambers, walls, and a grooved "sacrificial table" in New Hampshire has been called both a 4,000-year-old ceremonial site and a 19th-century farmer's root cellars. A century of argument has not settled it.
A seven-meter doorway carved into a sandstone cliff above Lake Titicaca is where legend says a fleeing Inca priest pressed a golden solar disk into the rock and vanished through a portal that opened in front of him, and visitors still press their foreheads into the niche to feel what he might have felt.
This cave produced the oldest leather shoe on Earth and the oldest known winery. The part nobody repeats is what stood beside the wine vat: storage jars with the heads of adolescents inside them, and one skull that still held brain tissue.
Found by accident in 1987 during a dam survey, this circular Bronze Age fortress in the Ural steppe was built with gates and doorways researchers say align to eighteen solar and lunar events, a claim, if accurate, of more precise astronomical design than Stonehenge.
Scattered across a remote Sulawesi highland valley, more than 400 carved stone figures, some over four meters tall, were made by a culture that left no name, no writing, and no agreed-upon date behind.
An 18-story subterranean city beneath central Turkey, capable of sheltering thousands of people and their livestock, that was lost to modern memory entirely until a homeowner broke through a wall into it in 1963.
Monumental stone statues carved by the Rapa Nui people on Easter Island, generally representing ancestral figures, with nearly a thousand standing across the island including the famous restored row at Ahu Tongariki.
A stone libation bowl pulled from a Bolivian farm in 1958 carries inscriptions some researchers read as proto-Sumerian cuneiform sitting beside a separate local script, a claim that would rewrite transoceanic contact with the ancient Andes if it held up.
A walled Swahili town of coral rag with a palace, several mosques, and indoor plumbing, emptied around 1600. Excavation turned up Ming porcelain, Venetian glass, and a pair of Spanish scissors. No Portuguese or Arab account of the coast mentions the place under any name.
