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

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

An original apothecary from 1792.

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

A nostalgic bibliographic gem.

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.

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

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The oldest continuously operating fish market in the United States.

Home to items never before seen by the public.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

At 207 feet, one of the world's longest continuous escalators.

The Pentagon is so large that it was planned like a city, complete with internal highway infrastructure.

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

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

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

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

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

Home of the physician who set the leg of John Wilkes Booth after the Lincoln assassination.

A monument to the center of the North American continent may be off by a few miles.

Elvis's own personal tropical hideaway.

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

Strange red rock formations that have been attributed to a higher power for hundreds of years.