This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

This nomadic monster has divided opinions as it prowls across Canada.

This remarkable museum sprung from one of the most important prehistoric archaeological sites in the world.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

A wall of chewing gum moonlights as collective art.

A walk through the historic city center, under the streets of Seattle.

A museum dedicated to the history and exploration of both popular music and science fiction.

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

This enormous censer uses a pulley system installed over 400 years ago.

Walking by this fence is like strolling along a portal to various fictional worlds.

More than 700 species live within this murky marvel of a swamp on California's coast.

New York City's smallest piece of private property.

The miraculous hydrant that saved the Mission District in 1906.

Towering basalt columns, a creation of fire and ice.

The interior of the Overlook Hotel in "The Shining" was based on this Yosemite original.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

A hotel and restaurant serving as the mecca of kitsch.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

The corpse bride of Portugal.