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

What's left of the ruins of the 1893 Columbian Exhibition, or World's Fair, also known as the White City.

One of the largest pieces of scientific equipment ever carried on a NASA space shuttle sits in a Chicago alley.

This cemetery is all that remains of a school for "wayward" girls.

The sign to a demolished amusement park now stands in front of a local library.

Recognized the world over as the home of the McCallisters in the 1990 movie "Home Alone."

Cold War missile launch site which has been converted to a public park.

All of Chicago's wood-paved streets are long gone but two alleys remain.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

No one knows how many bodies are in this vault in a Chicago public park.

A monument to the art of slicing people open.