Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

This freshwater spring fills with 10,000 gallons of water per minute.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

A 300-ship graveyard, with a few still visible at low tide.

The oldest family-run restaurant in the United States is a living museum of New Orleans dining history.

An eccentric inventor's castle home with its own indoor weather system.

Visible below the waves are memorials to the city's Gold Rush dead.

This spectacular track has run continuously since 1882.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

Enjoy an overnight at an old haunted B&B site of the Borden family murders.

A band of aerialists and circus performers putting on incredible shows in East Williamsburg.

One of the last Jazz Age "Wonder Theaters" in New York City.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Quite simply the largest tree in the world (by volume).

Rustic natural hot springs in the deciduous rain forest.

This quirky curiosity shop takes its cues from the world's bazaars.

Become a prohibition rebel.

A tiny red pebble marks what may be the quietest outdoor spot in the United States.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

The curiosities and wonders of pharmacy in a delightful historic building.