The world-record holder for the longest bridge stretching continuously over water.

This knobby, drooping New Orleans oak is a favorite place both for climbing and for meeting giraffes.

The stone labyrinth in this New Orleans city park was laid to symbolize healing in the wake of Hurricane Katrina.

After the parade, students throw their beads on the tree hoping for good luck on exams.

This New Orleans tree is filled with hidden chimes that produce a carefully tuned melody.

Storyville was New Orleans' historic red light district and hotbed of jazz music, sometimes referred to simply as "The District."

Washington's iconic carousel has a nice piece of Civil Rights history.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

The 28,000-year-old specimen is remarkably intact.

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

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

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

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

This statue of the "father of television" stands prominently in the United States Capitol.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The walls of the iconic dome are hollow and have a secret stairway.

Formerly known as National D-Day Museum, this collection commemorates the battles of Normandy and WWII.

This cathedral dedicated to Louis IX, sainted King of France, holds many secrets.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

This distinctive Crescent City tradition dates back to the days of horse-drawn carriages.

The oldest family-run restaurant in the United States is a living museum of New Orleans dining history.