This stately 19th century library pushed architectural boundaries at a time when the public library movement was just taking off.

A tribute shrine where the Space Invasion street art movement started.

A unique post-modern public space in the middle of the Warehouse District in New Orleans.

This Masonic lodge was the first major private building to be constructed in Washington, D.C. after the Civil War.

This coastal port saw one of the most significant battles of the Civil War.

This Civil War monument was designed by an eccentric architect and Gettysburg veteran.

In the middle of a busy airport, a statue honoring the astronaut who told Houston that Apollo 13 had a problem.

The "Key of Keys" for Washington, D.C. and the apocryphal landing place for the military campaign that started George Washington's career is now at the bottom of a well.

An 18th-century townhouse that once hosted guests of the president.

The hippo that stands on this university campus was once a drunken flea market purchase.

The National Park Service’s best-kept secret with views that rival any in D.C.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

Once home to the largest photo service in the United States.

The local community brought back this land to transform it into a nature preserve.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

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

A brass and marble scale model of the solar system embedded in the concrete.

The heaviest gold coin ever minted.

This lesser-known Frank Gehry building houses a treasure trove of cinema history.

One of the last Art Deco gas station still standing in Dallas.

A different Edgar Allan Poe built this charming Victorian home.

A melancholy jester sits on the grave of a famous 20th-century ballet dancer and choreographer.