The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

In the middle of a suburban Denver neighborhood is a cave that once provided solace for a prominent Ute chief and his family.

A seven-story 1920s mausoleum outside Denver houses thousands of remains.

The park preserves a single, rare species of carnivorous plant that spells doom for unsuspecting insects.

On the Oregon coast there is a natural hole that seems to be draining the sea.

A wrecked ship dating back to the American Revolution was only recently discovered off the Delaware coast.

These beautiful wineries were at the center of Lake Erie's "grape belt" back when the Midwest dominated American wine production.

Deep scars on the earth left by the Ice Age.

A memorial for the mustachioed record-setting runner.

A place for ship-lovers to watch the passage of freighters traversing the Great Lakes while learning about their history.

Pillars made of 700 pieces of luggage climb to the ceiling of Sacramento Airport's baggage claim.

Detroit’s Eastern Market has been transformed into an outdoor museum with colorful murals that address social issues and symbolize the city.

The world’s largest Masonic temple was saved by the White Stripes.

The 80-foot tire that looms over Michigan's I-94 was once a Ferris wheel in the New York World Fair.

The land is home to swimming ponies and a legendary 18th-century treasure.

This building at the south end of the boardwalk was once home to the U.S. Life-Saving Service and the U.S. Coast Guard before being rescued itself.

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

A 2,500-pound wooden nickel makes this woodworking museum easy to spot from the road.

These boots are made for selfies.

This crumbling Death Valley mining complex was known for its use of giant, 20-mule team wagons.

WWII-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers. .

After a water tower painting was accused of being an ad, a simple fix was made that gave the city a motto.

Prehistoric animals decorate this popular outdoor park.

The world's longest known cave system.