An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

The remains of Crystal Palace Great Exhibition of 1851.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

This 1920s Dutch barge is now a floating bookstore.

A historic house left in "dramatic still life."

Catacombs turned marketplace.

A hands-off space for graffiti artists to hone and display their skills.

A student driver's nightmare.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

Hidden beneath the streets of London is a secret subway that only carried mail.

This South London cemetery holds the remains of more than 15,000 people.

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

Obscured within a ring of trees, this abandoned World War II relic hides on a German hillside.

A tiny chapel clings to a precipice above Germany’s gemstone capital.

Now overgrown, these anti-tank barriers from World War II are sometimes called "dragon's teeth."

Art historians have debated the identity of this medieval stone rider since the 19th century.

A local museum honors the history of Bamberg’s unique cultural heritage: growing crops in the heart of the city.

A beautiful collection of taxidermy birds and rare pomological wax models.

A century-long search for a church that was never there.

The history of German architecture is explored across this fairy-scale mini-city.

A two-inch thick solid brass rod that extends an astounding one kilometer straight into the earth.

At this cemetery, artists are invited to design their own gravestones.