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 tunnel under the Capitol Building where Congress takes out its trash.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

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

This unassuming passageway played a key role in one of the most important events in U.S. history.

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

The early data processor factory founded in Washington for the 1890 U.S. Census went on to become IBM.

Amid the sprawling Defense Intelligence Agency Headquarters is one of Washington's least accessible museums.

The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

For 60 years, the academy had no permanent location until members voted Washington D.C. as its forever home.

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

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

A 19th century library favored by Edgar Allan Poe and H.P. Lovecraft, known by locals as "the Ath."

This twisty sign depicts the chain's first logo.

More than a century after her death, Little Gracie Watson remains one of Savannah's most often-visited residents.

Local myth claims this is a Sears catalogue home with its windows installed upside-down.

An eerie smiling woman looms above the granite tombstones.

The first public building in Savannah to offer air conditioning was a luxurious cinema that still operates today.

Hidden amid the old-world charm of Savannah is a museum dedicated to the world of oddities and criminal history.

This haunting tombstone comes complete with a heartbreaking story of love and loss.

One of Savannah's oldest and most haunted cemeteries, featuring graves desecrated by Sherman's Union Army.

This quirky curiosity shop takes its cues from the world's bazaars.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The privately owned cemetery that holds room for Washington's finest when they step down from life.