This church turned museum is dedicated to the last Mexica ruler, whose remains were allegedly buried under the altar.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

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

This beautiful train graveyard is one of the largest collections of steam locomotives in the Mediterranean and Europe.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Abandoned Nazi train station turned underground astroparticle laboratory.

After the construction of a nearby cathedral obstructed the view, the oldest belfry in Belgium was more than doubled in height.

These ruins reveal the remarkably intact layout of a Roman marketplace.

This is what trains will look like after the zombie apocalypse.

The abandoned ruins of a beautiful medieval castle just outside Barcelona.

Buildings that dynamite couldn't bring down were abandoned because of bathroom issues.

A beautiful 19th-century mansion slowly crumbled and became a 'ghost house' after World War II.

This ruined castle perched atop a rocky peak is a great place for a hike.

This centuries-old hotel hides a network of secret cellars and passages once used by smugglers.

An ancient water supply dating back almost 500 years can still be found standing in East Sussex.

Also known as Rye Castle, this 13th-century fortification later became a prison and held one of Rye's most famous criminals.

Henry VIII's forgotten castle was built by the gunpowder-obsessed king to be defended solely by cannons.

These mysterious mazes carved on the rock may be up to 4,000 years old.

Part museum, part piece of Arthurian-inspired history, this stately hall attracts King Arthur fans from miles away.

A whimsical cottage from the 1300s with a preserved Victorian-era post office inside.

It is said the legendary wizard once lived in this sea cave beneath Tintagel Castle.

A fantastic castle rumored to be the birthplace of King Arthur.

Shakespeare, David Bowie, Dr. Who, the Saxons, Druids and Romans are all claimed to have all made their mark on these massive man made tunnels.

A Victorian Fort built into the chalky cliffs that overlook the English Channel.