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.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.

The world's largest wooden structure.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

Curios, scientific antiques, oddities for sale.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Memorial of the Salem witchcraft hysteria in the town of Danvers, where it all began.

A popular European tradition makes its way to the states on one of America's most famous bridges.

When ecosystems collide in the arid Southwest.

A multi-storied adobe complex has been inhabited for more than a thousand years.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

See massive fossils that are over 200 million years old in northeastern Arizona.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Yale University's home for rare works, including the mysterious Voynich Manuscript.

The "world's biggest dinosaur" once housed a creationist museum in its abdomen.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The oldest working mechanical clock in the world.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.