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

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

The "dragon babies" of southeastern Europe.

A miniature train-ride through Slovenia's largest cave system.

One of the largest caves in the world open to the public.

Pilgrimage site for star-crossed lovers.

A complex, nine-layer maze on the grounds of a Venetian doge's playground.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.