This prison-turned-museum is a remnant of the Old West's grizzly, violent past.

This picturesque ghost town is located on the banks of the Suwannee River.

The high point on the 16th president's eponymous roadway is marked by a massive version of his head.

A monument to the egos of two railroad magnates that fell into decline along with their careers.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

The oldest inn in Kilkenny was established by the first convicted witch in Ireland.

This natural sea arch highlights Ireland's rugged coastal beauty.

360° views of the city plus five floors of optical illusions and hands-on science.

The fountain marks the area where hundreds of accused witches were burned at the stake.

A mysterious Neolithic tomb is perched along the edge of a modern golf course.

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

When ecosystems collide in the arid Southwest.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

This historic oak tree has been around for over 300 years and might last for 300 more so long as it doesn't fall apart first.

Georgia may have been on his mind, but this memorial in Florida shows that Greenville was really Ray Charles's childhood home.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

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

An architect's childhood fantasy treehouse made real.

Creek water that starts here has a 50/50 chance of ending up in the Atlantic or the Pacific.

One of the largest collections of wildlife art in the United States, built into the side of a cliff in rural Wyoming.