A centuries-old forgotten underworld lies beneath Malta.

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

This virtually windowless mass of smooth concrete is the only Catholic church in the city.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

Housed in a century-old building, this museum's dedicated not just to soft drinks, but to the free enterprise system.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

This elegant arc of a waterfall marks a religious turning point.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

This private residence was the template for one of the most beloved television homes of all time.

A striking 12th-century-style castle built on the edge of a cliff.

The glowing blue Nymphaeum of Emperor Tiberius.

A Prada store in the West Texas desert that is never open for business.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

A Memphis park where you can walk the whole Mississippi River in one go.

The oldest family-run restaurant in the United States is a living museum of New Orleans dining history.

Golden Gate Park's historic collection of plants.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Frida Kahlo's childhood home, now a museum of her life and works.

In this historic region, homes and churches are carved into ancient volcanic rock formations.