This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Hidden beneath the streets of London is a secret subway that only carried mail.

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

This 220-year-old house is a reminder of New York City's Dutch past.

The California capital city once stood 10 feet lower than it does today.

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

According to fictional Kcymaerxthaereal history, a powerful woman with a voice whose beauty could not be concealed found solace at this site at the Majestic Hotel in Singapore.

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.

For one day every month Barcelona's Estació de França transforms into a market for model trains.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

The oldest giants in Catalonia are now displayed in a 14th-century Gothic church.

18th century anatomical amphitheater of the Royal College of Surgery of Barcelona.

A once-secret library of Freemason history in Catalonia.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

One of Europe's largest supercomputers is housed inside of a disused chapel.

Stunning Roman aqueduct used for 1900 years and still standing.

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

Turntable anonymously received orphans, alms, and groceries.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

This cemetery features modernist statues as strange as its name.

Bronze plates placed around this Scottish fishing village form a true-scale model of the solar system.