An 18-mile-long tunnel for sewage waste will soon wind within the bowels of Washington, D.C.

Mirrored floors and arched shelves create the illusion of an infinite tunnel of books.

A small token of gratitude from freezing cold journalists who were given a warm haven while covering JFK's inauguration.

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

Military and first responders can test their skills in a Foggy Bottom mock station down in Georgia.

Before Nixon, "watergate" meant canals.

A historic neighborhood church is reborn as a psychedelic arts collective.

The rooster who crossed the road lives on forever in Takoma Park, Maryland.

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

There’s a special club house at the top for the bell ringers.

The walls of the iconic dome are hollow and have a secret stairway.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

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

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

A modern-day wunderkammer dedicated to Indianapolis history, Afrofuturism, and musical vibrations.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

A haunting tribute to pioneering photographer Clover Adams.