A strange rock with a sinister reputation lurks within the crimson waters of this Scottish glen.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

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

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

A whimsical village of unique treehouses resides in a Washington forest.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

A look into the Church of Scientology's deeply unfavorable view of psychiatry.

Towering basalt columns, a creation of fire and ice.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

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

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This geothermal hot spring hides beneath a slowly growing mineral dome.

This semi-secret storybook hedge maze is also the oldest garden in the city.

The angel of death appears to weep black tears at this grave marker.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

This knobby, drooping New Orleans oak is a favorite place both for climbing and for meeting giraffes.

This 700-year-old street food market features baby octopus and soy donuts.

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

The world's longest known cave system.