A haven for book enthusiasts across the street from Retiro Park.

Artist Natividad Sánchez wrote a new ending for one of Roman mythology's tragic love stories.

An ancient Egyptian temple in the middle of Madrid, Spain.

This magnificent Crimean estate was once a playground of the Russian elite.

A castle perched precariously over the Crimean Sea.

An incredible mosaic-lined monument said to have held the remains of an ancient Roman empress.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Psychoanalyst Carl Jung reported a paranormal experience after visiting this mosaic-lined Roman baptistry.

Italy's curious field of mud volcanoes is named for being both gross AND salty.

This lonesome Monterey cypress has survived centuries of wind, salt, and at least one attempt at arson.

A world-class observatory in the California desert.

An eccentric inventor's castle home with its own indoor weather system.

This working class sculpture pounds his hammer all the livelong day.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

A small part of Russia that does not touch any other part of Russia.

This memorial complex contains several mass graves for victims of the Siege of Leningrad.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

The museum chronicling a treasure hunter's dream, fulfilled.

A monument celebrating the idea of reaching inaccessible places.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

The celebrated eyesore created by starry-eyed sweethearts.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.