A small but immensely extravagant palace built by the "Night King."

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

World's largest cave was only discovered in 1991, and now offers tours to the public.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

A miniature village mimics the surrounding buildings so well it includes itself.

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

This historic, palatial theater is now one of the world’s most beautiful bookstores.

Historic medieval fortified city in southwest France.

The largest greenhouse in the world is home to over one million types of plants.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

Lavish royal estate punctuated with heated greenhouses.

An eccentric home in Sicily turns heads on a regular basis.

This fantastical house shaped like a seashell brings aquatic design to architecture.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A gallery of underwater art that can be visited by man and fish alike.

A 16th-century horror show built in a lovely Italian garden.

A mecca for India's Jains.

Erotic art covers the walls of the largest ancient pleasure palace.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Stunning Roman aqueduct used for 1900 years and still standing.

360° views of the city plus five floors of optical illusions and hands-on science.

Mountain where Jesus was first tempted by the Devil.

On stormy days debris from this unfinished and abandoned skyscraper rains down on the Bangkok streets.