A hands-off space for graffiti artists to hone and display their skills.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Artfully arranged bones of 5,800 Austrians.

Of all the houses that grace this neighborhood, only one is a testament to surreal architecture.

Mummified monks and the accidentally interred, in a 17th-century crypt.

A huge cathedral single-handedly constructed by one eccentric monk.

Strange masks and obscure costumes are housed in this old Madrid corrala.

Long-abandoned art nouveau baths beneath Milan's Piazza Oberdan.