100 massive sculptures in the Hudson River Valley.

The site of the first "historically true" UFO encounter in the U.S.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

The preserved house of a jazz legend still echoes with his music.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

A historic hotel that made a cameo in Hitchcock's classic film has no intention of letting guests forget its fame.

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

The restored and active Victorian-era final resting place of San Francisco.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

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

The remains of a ruined mansion memorialize the 1906 earthquake.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

Detroit’s downtown castle is one of the oldest structures in the city.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

This public baseball field is a beloved remainder from of one of the most historic stadiums in the country.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

The oldest surviving botanic garden in the United States.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

One of the oldest of its kind.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

A daily replay of the experiment that proved the rotation of the Earth.

The first American department store, and home to the largest operating musical instrument in the world.