This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

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

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

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

Home to items never before seen by the public.

The only Leonardo Da Vinci painting in the Western Hemisphere.

George Washington's dentures and Queen Victoria's dental instruments are in the nation’s official museum of the dental profession.

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

Walk through the history of American pop culture.

The childhood home of the Sultan of Swat is just a line drive away from Oriole Park at Camden Yards.

A winding district gerrymandered into the shape of a mantis.

Fascinating museum dedicated to the under-appreciated medical history of urology features some wince-inducing devices.

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

An eerie, decaying ghost town destined to fade into the forest.

A local farm's collection of unusual structures from a now defunct storybook amusement park.

Remnants of a storybook amusement park hidden behind a strip mall.

A former pillar of the Black community in Ellicott City.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

The "Sultan of Swat" once attended a school at the site of this baseball field.

A miniature city within a city, complete with traffic signs, signals, and streets to teach Baltimore's youth traffic safety laws.

The final resting place of an iconic drag performer is decorated with pearls and hot-pink lipstick.

A small 19th-century graveyard tucked away in the middle of a suburban neighborhood.