Rare recess caves fill this unbelievably beautiful Ohio park.

A favorite of Amelia Earhart, ranking among those rare bridges that can be crossed without changing sides of the river.

An office built to look like a giant basket.

An unassuming 13-acre park is home to over 12,000 roses.

America's first federal monument.

Look closely and you’ll notice that the color changes a third of the way up the tower.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

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

It was once the base for a series of domestic terror attacks.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

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

Oldest existing wire suspension bridge in the United States.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

A winding, cliffside stretch of road overlooking the Delaware River.

The dairy farm in upstate New York where nearly half a million people gathered for three days of peace and music in 1969.

"A hideous albatross in the Hudson River Valley."

This Central New York ghost town was once a prosperous railroad community.

The oldest continuously inhabited street in America.

The lost town of Neversink, sunk by New York City.