Coins and medals straight from the mint await visitors to this shop in the nation's capital.

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.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

An overlooked memorial honoring the local Washington residents who died in World War I.

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

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

The first memorial dedicated solely to the Black troops who fought for the Union.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

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

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

The "lovely red Vega" of the legendary record-settling pilot.

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.

A celebrity from the late Cretaceous period.

There's a crumbling old mansion inside the Smithsonian National Zoo.

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

Board a mine car and descend the #190 slope 300 feet underground into the Clark Vein of coal.

This museum is dedicated to a Hollywood icon.

Its original statue was deemed so ugly, locals called it “Scary Lucy.”

The first and only American institution dedicated to the enduring value of comedy in the United States.

Dozens of houses in the Adirondack Mountains are reminders of a literal "cottage industry" to cure people of a deadly disease.

A hamlet full of permanent Christmas spirit holds one of the earliest theme parks in the United States.

An encyclopedic collection of mammal penises.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created with the discharge from a geothermal energy plant.