These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

A storybook European village in Berkeley.

The neighborhood church casts a breast-shaped shadow that locals have come to call the “two o’clock titty.”

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

From a neon Rapunzel to a bike traffic meter to a street fair color scheme, the most opened drawbridge in the US is a veritable art gallery.

This former coal gasification plant found a curious second life as a popular public park.

A wall of chewing gum moonlights as collective art.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

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

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

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

The national park was once a plantation estate.

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

Largest Roman Catholic church in North America.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

Home to items never before seen by the public.

The United States Capitol's former columns still stand.

This futuristic bridge is one of the longest self-anchored pedestrian bridges in the world.

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

A "Texanic" (gigantic Texas) collection of Art Deco architecture at Dallas' historic Fair Park.

One of few surviving standpipe water towers in the U.S.