Four bald cypress trees in Lafayette Square, across from the White House, mark the southern edge of a 100,000 year old cypress swamp.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

These steeply terraced ruins are a stop along the Inca Trail to Machu Picchu.

The most decorated dog of World War I is preserved in the Smithsonian.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

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

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

This is why we can't have nice things on the Incan Trail.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

This stuffed pigeon of war had the very serious name "John Silver" until he lost a leg in battle.

An office built to look like a giant basket.

An abandoned asylum incorporated into a college campus.

Take a drunken tour inside the world's largest known geode.

Downtown Minneapolis mixed art and function by turning some of their sewer covers into works of art.

This fortress sits atop a centuries-old well system.

Decades before the scandal, this staircase on the river was a literal "water gate."

An obsolete, vanishing traffic device warns Cincinnati drivers away from middle-of-the-road obstructions.

The Grand Canyon of Texas.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

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