This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The word "Watergate" will forever be associated with the infamous scandal in 1972, but this fountain is famous in its own right.

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

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

Depending on who you ask, this controversial treehouse is either a charmingly creative child's playhouse or an illegal encroachment on public land.

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

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

Surrounded by traditional homes, this Tolkien-esque dwelling stands out on a quiet street in suburban Maryland.

At 207 feet, one of the world's longest continuous escalators.

This unique historical monument features large concrete spheres designed to resemble fallen stars.

The hidden offices underneath Memorial Bridge have been locked up since 1976.

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

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Look closely and you’ll notice that the color changes a third of the way up the tower.

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

A heroic pigeon that, through a barrage of gunfire, delivered a message that saved over 100 lives in World War I.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

Home to items never before seen by the public.

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

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.