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.

Perhaps the most scandalous statue of America's first president.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

A celebrity from the late Cretaceous period.

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

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

A haunting tribute to pioneering photographer Clover Adams.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

The house where John Wilkes Booth conspired with his co-conspirators.

The oldest continuously operating fish market in the United States.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

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

There’s a hidden military meme engraved on the World War II Memorial.

A nostalgic bibliographic gem.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

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

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

Home to items never before seen by the public.

The site of the climactic scene from the classic horror film is now a historic landmark.

Seller of surplus nuclear research materials.

The oldest continuously occupied public building in the United States.

A natural formation that resembles a camel resting in the New Mexico desert.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

Setting this massive marionette aflame rids Santa Fe of doom and gloom for another year.