The most metal church of all time was built in record time because of an international, pious pissing contest.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

An Art Nouveau gem hides beneath the layers of city grime obscuring this once-magnificent building.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A fountain standing as a testament to a doomed alliance.

A marvel of Byzantine engineering under the streets of Istanbul.

This narrow fjord-like bay is the largest ria in the Mediterranean Sea.

This Roman monument is surrounded by more recent construction, offering a stark contrast between ancient architecture and the modern urban landscape.

This "floating railway" is one of the world's oldest monorail systems.

Twisted buildings adorn the banks of the Rhine river.

This futuristic German television spire is actually the world's largest digital clock.

This concrete church spent a period of its history as a World War II bunker.

This German art chapel is perfect for those who like their worship hard, modern, and utterly alien.

A ruined castle stands atop a hill surrounded by dragon lore.

Climb inside an iron crystal magnified 165 billion times its normal size.

Three underground crypts and a pointed arch under the bell tower make this cathedral unique among Romanesque churches.

Geometry and mystery come together in an epic show of octagonal masonry.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

A statue dedicated to the antihero of the Nibelung legend.

The world's tallest church tower reveals a spectacular view to anyone up to the task of climbing the daunting staircase.

In this brilliant blue spring in Germany, legend has it that a sad mermaid learned to finally laugh.