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

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

The most accurate timepiece in the world.

Bar full of oddities, specimens, artifacts and homages to the great dime museums of the past.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

Art deco landmark on the outskirts of Washington, D.C.

The United States Capitol's former columns still stand.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

An astounding collection of medical specimens, including bits of President Lincoln.

The world's oldest continuously operating airport was founded by the Wright Brothers.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones' Locker.

This former asylum for Black Americans is haunted by its history of violence and racism.

A priceless collection of the Nation's cryptologic history.

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

This free, take-a-book shop seems like a trick but isn't.

The likeness of the Baltimore music icon was unveiled in time for the anniversary of his Senate hearings on music censorship.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

A museum dedicated to exhibiting remarkable outsider art.

The trials and tribulations of marking Poe's grave.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

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

Once America's tallest structure, now a Baltimore landmark.