La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

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

With over 10,000 lights, this engineering marvel lights up the city after dark.

Hidden up a dusty track off the Georgian Military Road is this fascinating waterfall with mountainous views.

Veryovkina Cave is more than 1.3 miles deep—the deepest known in the world.

The second-deepest known cave on Earth, hidden in an extremely remote mountain region.

This neon lit Georgian cave claims to hold the boulder Prometheus was chained to.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

These Stalin-era industrial 'death traps' hang lifeless above the city

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside.

Small church on top of a huge rock column.

The first skyscraper to include a Ferris wheel built into the facade.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Ancient rock-hewn town that witnessed key events of Georgian history.

Underground monastery and fortress.

A sculpture of the iconic East German car on four legs is a tribute to those who traveled to Prague seeking asylum.

This artificial cave looks like something out of a fairytale.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

A Jenga-style cylindrical tower of books that appears to go on forever.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

A two-way chairlift system between Zugliget and the highest point in the city.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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