This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

This massive swimming pool is the high tech home to the human-powered submarine races.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

Surrounded by traditional homes, this Tolkien-esque dwelling stands out on a quiet street in suburban Maryland.

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

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

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

Experience what life was like in Ireland during the Viking and medieval ages.

This 18th-century fort surrounded by a moat was used to store gun powder and ammunition, and now sits in the middle of a large park in Dublin.

An Industrial Revolution-era public work that purified water using nothing but sand.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

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

This historic boathouse was constructed using salvaged lumber from burned barns.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

This groundbreaking 16th-century map is known as "America's birth certificate."

Washington D.C.'s most famous pianist, composer, and bandleader still tickles the ivories outside Howard Theater.

Outside the Department of Transportation, a collection of artifacts honors the history of how we get around.

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

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

Mysterious installations bring levity and light to a sometimes stodgy city.

An amazing example of early-20th-century architecture, this church features marble transported from Utah.

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

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.