An unassuming secret door once led to a legendary watering hole.

The oldest still-existing mosque in the United States sits in a remote prairie in North Dakota.

This museum is a full-size replica of an original church constructed during the 13th-century.

Part of a secret 1970s nuclear defense program is now open to the public.

This replica of an 8th century burial ship actually sailed to Norway before returning home to Minnesota.

The world's largest Holstein cow.

A forsaken wonder in the middle of the East Side neighborhood.

This fountain was commissioned by a mother grieving over her son's passing.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.

Twin Peaks' real life Double R Diner has been restored to its damn fine television look.

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

While it is not equipped to peer into outer space this observatory looks like it was built on the moon.

This frequently-photographed waterfall takes only a short hike to visit.

Massive crater in central Oregon.

Along the Outback Scenic Byway, adjacent to hot springs, this human-made geothermal feature takes unexplained breaks.

A haunted hot springs hotel that went from healing retreat to asylum before it was restored.

The wooden airship was the largest flying boat ever built.

Home of Howard Hughes' Spruce Goose.

A 36-ton remnant of the last Ice Age now resides amid picturesque vineyards.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A ring of creosote bushes that are estimated to be 11,700 years old.

This strangely vacant Western amusement seems to be an empty tribute to residents of Lucerne Valley.

Cooks at this tiny takeout spot grind their rice flour in a stone mill each morning for perfect cheung fun.

Not-so-fearsome tiny trolls live under this wooden train trestle in Portland.