Pyrmaid at Teotihuacan, Mexico.

Pyrmaid at Teotihuacan, Mexico. Image by pmoroni / CC BY-SA 2.0

The pyramids of Teotihuacán, northeast of Mexico City, draw tourists in their thousands each year, even though little has been known about the ancient civilisation that built them – until now. Archaeologists have discovered a large amount of mercury under one of the pyramids, along with several artifacts, that could shed light on one of the Americas’ greatest cultures. Read more: theguardian.com