Hungarian Jews were ghettoized during the Second World War, but little remains of the original wall that closed the Jewish people off from the rest of the city.

Legions of Roman soldiers bathed in this ancient spa complex under a Budapest transit station.

The site is dedicated to an investigative journalist whose murder triggered a political uproar that changed Slovakia forever.

Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

A history of heat is on display at this unique Austrian museum.

Museum featuring strange and enchanting toys of the past.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

This little-known relic crypt holds stolen parts of a Roman Empress.