After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

Look closely and you’ll notice that the color changes a third of the way up the tower.

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

Before Nixon, "watergate" meant canals.

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

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

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Perhaps the most scandalous statue of America's first president.

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

Largest Roman Catholic church in North America.

The national park was once a plantation estate.

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Golden Gate Park's historic collection of plants.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

San Francisco's newly reopened hands-on science museum.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.