This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

An underground city of salt.

This picturesque castle in Poland has a rich history, including a legend that ties it to lost Incan treasures.

The majority of the highest mountain in Poland is actually located in a different country.

One of the few cold geysers in Europe, its eruptions are powered by carbon dioxide.

This region of Slovakia boasts some of the most plentiful opal mines in the world.

A gorgeous stone viaduct crosses over a bucolic valley.

An unusual cave filled with rare alien-looking aragonite formations.

Too much gossip or just missing curfew could land you in here for a couple of days.

This statue points to another unusual companion work of art often overlooked by visitors.

A sculpture of a beloved local figure, who tipped his top hat to everyone he passed on the streets of Bratislava.

An ode to a soldier who came to town, fell in love, then began making his own sparkling wine.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

Miles of man-made caves and tunnels are currently used for cultivating mushrooms.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.