Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

This Welsh dockyard was the site of the not-so-secret construction of the Millennium Falcon for the original Star Wars trilogy.

This arcade is one of the last places to catch a public performance by the now-defunct ShowBiz Pizza's house band of animatronic animals.

A prehistoric landscape hidden in the cliffs of Maha'ulepu.

This ruined fort and statue are a testament to the last king of Kaua‘i’s savvy diplomacy skills, which briefly brought Russians to Hawai‘i.

Floor-to-ceiling frescoes by local art students cover the interior of a nearly 200-year-old church.

When the sun sets, the customers arrive—but they’re not human.

A gardener's enduring labor of love is spread throughout a small Vermont town.

This pier made of ice and constructed over the Antarctic winter is used when the resupply cargo ships arrive in summer.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

This jagged colossus of a building is mostly held together by an enormous concrete exoskeleton.

The ruins of an 18th-century mansion that was once named "Mistake" by the man who had it built.

A historic bridge no one is allowed to cross.

In the mountains of West Virginia is this perfectly preserved Art Deco train station.

Despite what a Thai tourism board might want you to think, this white-sand beach is in fact located on a Scottish island.

This isolated island is often capped by its own fluffy cloud.

A man's home is his castle.

The oldest residential street in Europe also features an optical illusion.

The way that light hits a stained glass window on a specific day is one of many "clues" to a mysterious treasure.

No one knows who created the statues or if they are arranged properly—let alone the artwork's real name.

A unique Shinto shrine filled with bunnies and wordplay.

The world's largest drain sits below the city of Kasukabe, Japan.

Every summer, this shrine sets up a tiny drinking fountain reserved for thirsty apians.