A historic bridge no one is allowed to cross.

A street in front of NASA's D.C. headquarters has been named in honor of the Black women who were essential to early spaceflight.

Over the last century, this elegant columned facade has been home to the headquarters of a bank, several nightclubs, and a restaurant.

The ruins of an 18th-century mansion that was once named "Mistake" by the man who had it built.

Near the summit of Mount Washington, a stone monument remembers a life lost to one of the mountain's infamous storms.

Mumbai's angel.

This site is believed to be connected to the oldest house in Arlington County.

A graveyard that dates back over 200 years stands near a busy shopping center.

A small brick parlor house and artist's studio located in the wilderness is surrounded by imposing suburban palaces.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

The last vestige of a once substantial orchard and farm in the suburbs of Northern Virginia.

Designed as a reminder of one of the darkest moments in Austrian history.

The Conduit Road Schoolhouse is one of the last one-room schoolhouses remaining in Washington, D.C.

A rare example of a rural school in Washington, D.C.

Narrow gorges and deep pools created by long-ago glaciers.

A glimpse into early 19th-century education.

Along the edge of this fountain are 365 smaller fountains that represent the days of the year.

These unique rock formations were created during the Ice Age.

Rub it for a bit of good luck.

Known as "Toronto's Flatiron."

These relics of the city's past now exist as a prominent modern feature.

A former pillar of the Black community in Ellicott City.

The smallest covered bridge in Maryland.

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.