This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Macabre astrological automaton clock dating to the late 1400s.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

Ever-growing collection of devils in art.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

A former imperial sea-fortress and Soviet prison.

Beyond the usual stories that attend old prisons, this one has deep bloody undercurrents.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Besieged by war, this castle ruin has crumbled into a peaceful picnic spot.

A church of bones, decorated with 40,000 human skeletons.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.