Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A local prank turned town icon.

This elaborate towering structure was once famed for its revolutionary height.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

At 207 feet, one of the world's longest continuous escalators.

These unusual rooms on wheels are holdovers from the 1960s.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

The romance of early commercial flight still fills this Art Deco destination.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The taxidermy remains of the most popular pony in children's literature.

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

During the summer, surfers in Alaska take advantage of this inlet’s unusual water patterns.

Don't be a grizzly man. Get personal with Alaska's wild bears from the safety of this conservationist camp.

An Alaska livestock farm devotes itself to harvesting wool from creatures that once ran with mammoths and sabertooth tigers.

While not recognized by Guinness, this chocolate waterfall is likely to be the world's largest.

Four-story concrete hotel never opened to customers.

A trading post in the North Pole where children send letters.

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

Egyptian Revival obelisks still rise over the old mine shafts.

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

Lovingly nick-named the "Brick Dick" this municipal tower was winner of the World's Most Phallic Building Contest.

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

This empty Detroit high school was too expensive to maintain or destroy.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.