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.

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

One of 100 “Whaling Wall" murals painted in 13 different countries by a renowned marine life artist.

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

The first American department store, and home to the largest operating musical instrument in the world.

This elaborate towering structure was once famed for its revolutionary height.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

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.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

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

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

A spectacular tribute to statesman and philanthropist Andrew Mellon.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

A much-maligned monument to teetotalism.

Go take a picture with the inventor of the daguerreotype photographic process.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

A home that witnessed Civil War combat on the Sunken Road has the battle scars to prove it.

The Kirkland Monument remembers a selfless Civil War hero who braved the battlefield to give water to his dying enemies.

These trees are living witnesses to events that inspired poet Walt Whitman’s service during the American Civil War.

This estate on the banks of the James River was home to a Founding Father, two presidents, a famous bugle melody, and what some say was the actual first Thanksgiving.