With its two craggy rock formations protruding toward the clouds, Waqra Pukará, which translates to horned fortress, is one of Peru's most perplexing sites. While it's often overshadowed by neighbouring Machu Picchu some 80 miles (130km) away, the ancient site is one of the country's hidden historical gems.

Despite the site's sheer scale, little is known about it. The terraced rock has obvious parallels to the Incan Empire, yet archaeologist Oscar Montúfar told the BBC that there is archaeological evidence tying the locale to earlier cultures, including the Pukará civilisation, which flourished between 1400 and 550 BC. Signs of the Tiawanaku, Wari, Canchis and Inca civilisations are also evident. But what was the site used for?

The world’s most baffling architectural mysteries SOLVED