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

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

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

This semi-secret garden in south Seattle emulates a traditional Japanese garden using the plants of the Pacific Northwest.

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

A Bibliophile's Dream.

The largest self-built castle in the U.S., six decades in the making.

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.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

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

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

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

A modernist landscape of water and sci-fi concrete.

A hand-built folk art installation covered with messages of God's love.

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

One part antique store, one part curiosities hodge-podge.

All that's left of the quintessential "cabin in the woods."

The rocks in this arid basin leave trails of movement behind them.

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

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

Scores of vintage street lamps shine along L.A.’s Miracle Mile.