The Thirteen Towers of Chankillo
On a desert ridge in Peru stand thirteen small towers in a line. Watch from the right spot, and the Sun rises over a different tower each week of the year.
What was reported
Chankillo, in the coastal desert of northern Peru, is a complex of ruins that includes a hilltop fort and a row of thirteen square towers spread along a low ridge, like the teeth of a saw. For a long time, nobody was sure what the towers were for.
In 2007, archaeologists showed that from two observation points, the towers span the full range of sunrise and sunset positions over the year. The Sun rises behind one end at the June solstice and the other at the December solstice, moving across the towers in between.
Explanations offered
It's the oldest known solar observatory in the Americas, probably used to keep a calendar for festivals and farming. It became a UNESCO World Heritage Site in 2021.
- When
- Built about 2,300 years ago
- Where
- Casma, Áncash, Peru
- Witnesses
- Archaeologists
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.
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