Taking the subway here means doing so over a bridge located in the middle of an estuary.

A fountain standing as a testament to a doomed alliance.

A marvel of Byzantine engineering under the streets of Istanbul.

This wildlife refuge is home to more than 200 species of birds, as well as monkeys, lizards, and other wildlife.

The same water that fills a luxury resort’s pools feeds these free hot springs in the rainforest.

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

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

A giant chess set, minus the psychedelic drug trip.

A plaque outside the San Jose airport commemorates the insect's arrival to the West Coast.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

A modest reminder of treacherous waters at the Golden Gate.

The United States' first transcontinental automobile road came to its end at this spot in San Francisco's Lincoln Park.

A winding path built in secret on the edge of the continent.

Celebrating the transformation of trash into objects of beauty.

Experience Larry Spring's self-taught "common sense" laws of physics.

A trash dump made beautiful by nature's power.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

Inside the world's largest seed bank, WWII botanists elected to starve to death rather than compromise their collection.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

San Francisco Bay's ghost town.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The first declared National Monument in the United States.

The celebrated eyesore created by starry-eyed sweethearts.

Pillars made of 700 pieces of luggage climb to the ceiling of Sacramento Airport's baggage claim.