Four-story slides send people whizzing through the math department at this Munich university.

The mouldering remains of a disgraced British children's icon are hidden in the brush of a public park.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

This Roman quarry once held secret masses and smuggler's contraband and is now home to rare species of bats.

Final resting place of John Middleton "The Childe of Hale."

Giant statue of a disembodied head.

The town of Argleton has a postal code and appears on maps and even real estate listings, yet it does not exist.

Much of what constituted mid-century Liverpool now litters a beach outside of town.

One of the oldest amusement rides in existence was a huge disappointment to its creator.

Once upon a time these giant concrete tanks were used by local fishermen to clean their wild-caught mussels.

The remnants of a depressing public toilet are now a hub of ever evolving street art.

This 19th century police station now puts the history of the Manchester City Police on display.

This massive memorial commemorates those who died in the Manchester Arena bombing.

A tiny, heartwarming piece of art hiding in plain sight.

Fulham F.C. imploded once everyone excised its giant, hated tribute to the King of Pop.

The fake World Cup prize was secretly created after the first one was stolen in 1966.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

The small bright red pillar survived the 1996 Manchester bombing virtually unscathed.

A tiny, hidden alleyway dedicated to the father of meteorology.

This nondescript building hides an entrance to an underground nuclear tunnel system.

This tiny watering hole claims to have the smallest bar counter in Europe.

Despite having a dome made of papier-mâché this tiny observatory has survived for over a century.

A giant wooden soda bottle pays homage to a distinctly British drink on the very spot where it was invented.

A hunk of prehistoric lava rests amid the Gothic architecture of a campus quad.