One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

When ecosystems collide in the arid Southwest.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

Despite the ever pressing encroachment of urban sprawl this grand New Orleans manse still stands.

A common entry point to the Griffith Observatory trail holds its own wonders.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

Rustic natural hot springs in the deciduous rain forest.

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

Private collection of art inspired by cabinets of curiosity.

An enormous park-like oasis, full of famous Chicagoans' graves.

Welcome to old Florida, where a 1940s mermaid show is still enchanting visitors.

The magic's in the hole!

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

These eerie outliers of the lightning bug family glow a mysterious blue color.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

One person's lost luggage is another person's treasure.

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

Possibly the most beautiful carillon in the world, set atop Iron Mountain in Florida.

Sniff the Titan Arum's rotting flesh.