Relics of the 1894 Midwinter Exposition continue to delight visitors today.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

Look closely and you’ll notice that the color changes a third of the way up the tower.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

A historic arena where the Beatles played their first concert in the U.S.

Washington's iconic carousel has a nice piece of Civil Rights history.

There’s a special club house at the top for the bell ringers.

This poor little statue is the most vandalized memorial in Washington.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

The oldest continuously operating fish market in the United States.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

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

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

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

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

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.