Fittingly, America's museum of architecture is itself a magnificently designed old building.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

Captain John Smith thought these cliffs were amazing in 1608 but sharks thought so 20 million years before him.

This lovely pocket park is one of the most under appreciated in D.C.

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

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

This Asian-inspired tower in a lush urban park provides spectacular panoramic views of Baltimore.

Two dozen pinball games hidden away inside a most unlikely location.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

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.

Examine the impact of the horse on Great Plains culture through exhibits on ranching, rodeo, and the Native American way of life.

Once a sewer culvert, this road tunnel now offers cyclists and pedestrians a subterranean stroll under the C&O Canal.

A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

This grand gothic brewery has been pumping out suds for over a hundred years.

People escaping slavery may have hidden inside a corpse vault.

This small hilltop church weaves the urban history of Washington, D.C. with the national history of the United States.

This fertility idol of questionable authenticity inspired an iconic Indiana Jones artifact.

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

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

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

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

A brass and marble scale model of the solar system embedded in the concrete.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.