This nine-story building is the oldest standing skyscraper in D.C.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

The span is crooked and made from two older recycled bridges.

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

The national park was once a plantation estate.

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

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

"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!”

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

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

The oldest continuously operating fish market in the United States.

Where the U.S. government kept its actual treasure, before Fort Knox.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

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

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

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

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

An ivy-covered arch bridge dedicated to Tejano music singer and legend Rosita Fernandez.

A mysteriously abandoned campsite in San Angelo State Park.

World's smallest skyscraper, the product of a remarkable con.

Belly up to the bar in Cowtown, don't forget to buy some boots.