Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

This sprawling bookstore spans four floors and has more than a million books in stock.

A crumbling mountain resort that looks like it was abandoned in an instant.

George Martin's Caribbean recording studio now rots within the shadow of an active volcano.

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

Through the decades, Black music stars have performed at this historic hub for music and the arts.

A public art jibe at one of the United States’ oldest and longest-serving senators.

The first memorial dedicated solely to the Black troops who fought for the Union.

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

A historic arena where the Beatles played their first concert in the U.S.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

The span is crooked and made from two older recycled bridges.

This poor little statue is the most vandalized memorial in Washington.

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

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

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

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

The famous abolitionist’s preserved estate is one of Washington's finest monuments to its great Black citizens.

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.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.