The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

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

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Suffocating dogs was a common spectacle in the fumes of this noxious cave.

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

The mark of the Devil's horns on a marble column in Milan.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

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

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.