Beautiful Gothic-inspired lighthouse stands out among the run-of-the-mill striped fare on Bodies Island.

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.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

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

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

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

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

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

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

Home to items never before seen by the public.

The brainchild of Eleanor Roosevelt, her "Little Village" was a collectivist dream.

This university transit system is a 1970's vision of the future.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

Near-constant high winds deform the trees on Spruce Knob, the highest point in West Virginia.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

The narrowest house in America is seven feet of pure spite.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.