A lush indoor jungle fills this bustling Madrid transportation hub.

Commonly acknowledged as the only public monument to the Devil himself.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

The largest and most famous wax anatomical collection anywhere in the world.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The glowing blue Nymphaeum of Emperor Tiberius.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

Venice's "Island of the Mad."

The oldest operating pharmacy in the world features 800-year-old recipes.

Stalactites and stalagmites in a beautifully lit cave.

Thousands of well-dressed mummies below a monastery.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

The alpine falls where Sherlock Holmes apparently met his demise can actually be visited.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

Budapest's Communist-era statues, banished to the suburbs.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

Once the home of a hermetic monk, this cave now houses a small church.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Museum dedicated to the terror regimes of Hungary.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.