A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

A museum dedicated to the alleged Roswell Incident.

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

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

The first artificial white water river course in North America cuts right through an Indiana city.

Considered by many to be one of the most dangerous highways in Alaska.

A rare chance to get up close and personal with a 13-mile ribbon of ice near downtown Juneau.

The king of U.S. high points towers over every other peak on the continent.

What happens when a sculptor has to find a way around a 100-year-old copyright.

Known as "Toronto's Flatiron."

One of the largest underground systems runs under Canada's largest urban center.

This urban oasis is a marvelous meld of music and landscape architecture.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

This groundbreaking 16th-century map is known as "America's birth certificate."

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The "lovely red Vega" of the legendary record-settling pilot.

Perhaps the most scandalous statue of America's first president.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

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

Tour the sci-fi-esque reality of governmental disease management.

An underground magnet for ever-changing street art.

This magnificent herd of stampeding elephants has been frozen in time for over a century.

Avoid gangster interaction while window-shopping.