You're looking at the Soto dolmen in Trigueros, Spain—and you're right to be amazed. This prehistoric tomb has been home to rituals of life and death since 4200 BC, and now after nine years it's been restored to its prehistoric glory.
Measuring 60 metres in diameter and 3.5 metres high, visitors troop down the 21-metre passageway into the central chamber, basked with sunlight which pours in through the doorway. The largest of over 200 megalithic tombs that dot the Huelva province, New Scientists explains its origins:
The stones that support the Soto dolmen's interior were originally arranged as a Neolithic stone circle similar to Stonehenge, before being repurposed in this structure. When Don Armando de Soto uncovered it in 1922, he found eight bodies inside, posed in crouching positions near the wall and surrounded by stone utensils, pottery and decorative items.
Don't worry if it made you think of the X-Files, though. That's a perfectly natural reaction. [New Scientist]
Image: Getty/AFP/Cristina Quicler/Gogo Lobato