A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

Internationally-recognized arts center housed in a century-old former military barracks.

Concrete strongholds stand guard over the Golden Gate.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

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

A spectacular tribute to statesman and philanthropist Andrew Mellon.

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

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

An overlooked memorial honoring the local Washington residents who died in World War I.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

A massive, majestic mammal watches over pedestrians from his perch atop a former B.P.O.E. lodge.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

The narrowest house in America is seven feet of pure spite.