Home of a 28-foot tall stalagmite known as the War Club.

Spectacular mineral formations fill these caves, which have been used for everything from smoking meat to stashing illicit liquor.

This former fire tower found new life as a communications hub complete with a scenic overlook.

The original span of a high bridge across the deep Crooked River Gorge has been preserved for pedestrian use.

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

One part local history, 99 parts gruesome haunted house.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

The world's brightest bioluminescent bay.

Ho Chi Minh's perfectly preserved body has been on display here since 1975.

Home of the unusual art of water puppetry, one of Vietnam's oldest curiosities.

World's largest cave was only discovered in 1991, and now offers tours to the public.

A gruesome memorial for those lost in this area during the Khmer Rouge genocide.

5,000 skulls in memorial to those killed by the Khmer Rouge.

The walkable ruins of an 19th century hotel, destroyed in a horse cremation gone wrong.

A careful eye can find hundreds of dinosaur tracks running along the Connecticut River.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

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

A beautiful geyser under environmental threat.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

Curious cave that stays a cool 56 degrees all year long.

Thousands of artifacts relating to human sexuality, including the world's largest sex bike.

Rushing water plunges over a 100-foot drop created by an ancient lava flow at this majestic waterfall.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

An absolutely beautiful 200-foot stained glass installation traces the evolution of knowledge.