The true meaning behind this sculpture remains unknown.

From cartoon characters to tiny tanks, a guerilla sculptor's little bronze statues are hidden throughout the city of Budapest.

On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

A forgotten graveyard lost in the tangles of an overgrown garden.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

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

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Fantastic views and thousands of love locks.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

A student driver's nightmare.

A kaleidoscopic warehouse-maze of handmade neon signs.

The Greek island's old British cemetery feels like a forgotten garden.

This once architecturally advanced housing complex is now a haven for squatters that still bears the scars of war.

One of the greatest collections of coins in the world is housed in the former mansion of an archeological pioneer.

A unique work of automotive art calls this shopping center home.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

Seven mini rowhouses fill the gap between 54 and 70 Westerstraat.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.