For just a few hours each morning, this market serves specialties from the city's shrinking Chinese-Indian community.

Rumors persist that a bottle of whiskey is sealed within this Demijohn-shaped adornment.

The well-preserved remnants of a bridge that once made up a WW1-era military railroad.

It was once the base for a series of domestic terror attacks.

Once a sewer culvert, this road tunnel now offers cyclists and pedestrians a subterranean stroll under the C&O Canal.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

The world's oldest soul food restaurant is also one of its best.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

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

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

Government testing at the asylum briefly explored using marijuana as a "truth serum" on Nazi prisoners of war.

The oldest continuously operating fish market in the United States.

An Industrial Revolution-era public work that purified water using nothing but sand.

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

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

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

The first museum in the U.S. to address human rights issues in China.

A spectacular overlook of the Little Grand Canyon of the San Rafael River, a deep sandstone gorge streaked with orange, red and white in a remote, uncrowded part of Utah.

The seat of the lost Ryukyu Kingdom has survived numerous fires and wars over the centuries.

A sandstone lamp post in Mumbai's business district honors the war efforts of the Port Trust and its employees who fell during World War I.

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.