This iron and wood Civil War city-ship was the first vessel to be sunk by an electrically detonated torpedo.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

Dedicated to the art and science of glass in equal measure, this space is as much laboratory as museum.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

One of the largest underground systems runs under Canada's largest urban center.

The self-made house sculpture of an outsider artist who named himself "Chief Rolling Thunder."

A monument celebrating the idea of reaching inaccessible places.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

The museum chronicling a treasure hunter's dream, fulfilled.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

"We Seceded Where Others Failed."

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The 80-foot tire that looms over Michigan's I-94 was once a Ferris wheel in the New York World Fair.

The rusting remains of the largest assembled WWII fleet on the West Coast.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.