This incredible collection of vintage pinball machines can be played at 25 cents a pop.

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

The neon signs from Las Vegas' past find their final resting place at this unusual graveyard.

A hidden art gallery in an abandoned Warsaw fort.

Warsaw's fantastically preserved gasworks...almost.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

An artificial hill and apparent calendric structure built in the Early Middle Ages immortalizes a legendary Polish princess.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

This man-made mound monument was built out of soil from all across the Polish empire.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

Real bones which are said to have belonged to a Polish dragon.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Some people believe that this makeshift space monitoring station received transmissions from clandestine cosmonauts.

A mysterious stele of unknown origin sits on the peak of this curious mountain.

This Torino museum honors a soldier who kept the city safe using barrels of exploding gunpowder, losing his life in the process.

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

The astonishing collection of an infamous criminologist.

Housing the groundbreaking maps and globes of Gerard Mercator.

A museum celebrating the Canadian forces that liberated Belgium from the Nazis replete with battlefield miniatures and multiple Gardens.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

A Museum of Psychiatry in a still-operating mental institution.

An open-air sewer system that was covered piece-by-piece over 300 years.

This former Masonic lodge has been transformed into part museum, part bar, all awesome.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.