This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Bacteria and algae give the salty water its bubblegum hue.

An ancient Egyptian temple in the middle of Madrid, Spain.

A beautiful but toxic fountain of mercury.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.