Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.

This giant wooden treehouse within a sprawling garden has its own eatery.

The sign at the garden gate reads: "These Plants Can Kill."

A lone pole once used to display a man's corpse now stands empty, but the memory remains.

This enchanting Victorian estate was home to the world's first hydroelectric power generator.

A 18th century graveyard and its astonishing cortege of macabre iconography.

Hear the quietest sound from across the dome.

This South London cemetery holds the remains of more than 15,000 people.