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

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

A line of blue paint marks the route of the inaugural parade.

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

A building shaped like the Army Corps of Engineers logo, because why not?

The house where John Wilkes Booth conspired with his co-conspirators.

A haunting tribute to pioneering photographer Clover Adams.

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

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

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

Fittingly, America's museum of architecture is itself a magnificently designed old building.