Where Aleister Crowley taught magick in "La Chambre Des Cauchemars," his "Chamber of Nightmares."

The world's most active stratovolcano is almost always erupting.

An early-20th-century "dacha" village of quaint cottages curiously located in a modern part of Moscow.

A medieval wash house where people washed clothes in a river allegedly formed by the tears of a mourning nymph.

The now-overgrown beach resort was once frequented by Yugoslav military elite.

This ruined fortress was the stronghold for a persecuted medieval leader and his infamous Assassins.

A tilted half-timbered house from 1672 is built into a salvaged segment of a medieval wall.

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

Deep in the countryside lie the remains of one of the grandest Roman dwellings in Britain.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

A museum glorifying the life of Stalin, located in the city of his birth.

Fortified homes of highland warriors that are still in use today.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

Underground monastery and fortress.

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside.

Ancient rock-hewn town that witnessed key events of Georgian history.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

A stunning two-story timepiece within a medieval Brick Gothic church.

France's highest manned weather station is the only one still inhabited by meteorologists.

This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

Tiny memorials honor individual victims of the Holocaust.

Peeing dogs guard the Roman hunting goddess atop a fountain at France’s Château de Fontainebleau.