This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

The land is home to swimming ponies and a legendary 18th-century treasure.

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

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

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

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

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

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A haunting tribute to pioneering photographer Clover Adams.

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

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

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

These abandoned waterworks are crumbling into the Potomac River.

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

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

This Maryland farm is known for its amazing corn mazes and its 30-foot junkbots.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

Built by the patriotic residents of Boonsboro in a single day.

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

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

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