A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

The oldest continuously operating pharmacy in Europe.

This kitsch eatery is chock-a-block with bric-a-brac.

An underwater statue of Christ blesses the coral reefs off Key Largo.

The largest freshwater lake in the Florida Keys.

A creepy statue of a hooded ghost hauls itself up from the water in a historic Lithuanian city.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

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

The past, present, and future of Russia's signature alcohol is remembered in the world's only museum dedicated to the starchy spirit.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

Everyone from Alan Ginsberg to The Rolling Stones has stopped by this classic dive bar.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

An enchanting natural wonder in Puerto Rico's Camuy River Park.

This popular cave pool is truly magical, despite the crowds.

The tree is thought to be the oldest oak in Texas and was once crowned state champion for its monumental size.

On Hilton Head Island this bronze King of the Sea rules all things briny—and lets you know if you’re late for lunch.

Despite being burnt down multiple times, the ruins of this South Carolina church are still standing.

A statue honoring 44 continuous years of greeting passing ships.

An early-19th-century hotel with a past that is steeped in the Civil War.

This lovely burial mound is actually a replica that was installed after archeologists excavated the original.

One of corporate America's best-kept secrets is also one of the most publicly displayed.

This bar hosts an ever-evolving napkin art installation devoted to an American president.