This former INS center is now home to a thriving community of artists, from performers to painters to architects.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A beautiful but toxic fountain of mercury.

Hidden within an idyllic suburban garden is a memorial dedicated to the victims of a terrifying spree of killings committed on U.S. soil.

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

A former major munitions plant that has been converted into a sprawling art space.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

The romance of early commercial flight still fills this Art Deco destination.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

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 oldest continuously operating fish market in the United States.

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

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

Decades before the scandal, this staircase on the river was a literal "water gate."

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

When it comes to handsignals (and colonialism) rock always beats scissors.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

Perhaps the most scandalous statue of America's first president.

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

Obscure Freemasons still live in D.C.’s largest private residence.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.