Whitewashed mosque contains the world's largest carpet.

Twisted girders are all that remain of an Icelandic bridge that was wiped out by a combination of volcanic heat and glacial floods.

Iceland's largest lagoon is home to stunning multi-colored icebergs.

A sulfuric martian landscape that looks far better than it smells.

Rising from the sea like a stone monster.

Medicinal spa created with the discharge from a geothermal energy plant.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Electrical curiosity museum housed in an old transformer station.

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

One of seven Jewish catacombs in Rome and one of only two open to the public.

Pilgrimage site for star-crossed lovers.

A unique hanging cable-car navigates through Dresden, the oldest suspension railway in the world.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

When the rain falls, this drain system turns into a musical instrument.

The tallest outdoor elevator in Europe rockets passengers on a dizzyingly precarious ride to the top of a mountain.

This is not only one of the oldest collections in Europe, but also possibly the most beautiful.

Architectureal fantasy quarter of Rome.

A subterranean house of worship carved right out of the bedrock.

An abstract monument to a symphonic composer.

Moscow's imposing monument to the Space Age.

Museum celebrating the achievements of the Soviet space program.

Stalinist skyscraper built with help of cryotechnology.

A 20th-century picture show in 3-D.