The commemorative stone column conceals a secret laboratory.

This 135-year-old weather station studied the effects of the climate on human health.

High in the Sacramento Mountains, a facility dedicated to studying the sun.

More than 10,000 small mirrors cover the curved surface of the world's second-largest solar oven, located in a remote village in Uzbekistan.

This Scandinavian island is the site of the first modern observatory.

Numerical symbolism abound at East Asia's oldest observatory.

The site of the original experiment that would be used to disprove the theory of luminiferous ether.

Hidden behind a YMCA stands the remains of a ceremonial site that dates back hundreds of years, whose ground is still considered sacred to many Hawaiians.

Once home to over 8,000 exiled Hawaiians suffering from Hansen's Disease.

A UFO scrapyard in the California desert.

A model of a galactic embassy is hidden in plain sight along the highway, proposed by a UFO religion to find the aliens that created life on Earth.

The New England cabin where an infamous British occultist conducted experiments in "magick".

It's a repurposed treasure trove of history, located just an hour away from Acadia National Park.

Floor-to-ceiling frescoes by local art students cover the interior of a nearly 200-year-old church.

Located in the historic home of a newspaper publisher, this museum is dedicated to the Freedom of Speech.

This museum on a college campus pays tribute to the Arctic and to two explorer alumni.

This state-of-the-art planetarium takes architectural inspiration from the sun itself.

Statue commemorating the use of ether in anesthesia.

This former Masonic hall has been turned into an art project that uses even more metaphysical iconography.

Once the largest public hospital for the mentally ill was also surrounded by controversy.

Run by a eugenics advocate, this aging institution conducted secret radiation experiments sponsored by Quaker Oats.

The sprawling, eccentric estate of Ames and Ames, a brilliant botanist, and a genius inventor and artist.

Former private property that was hidden up a trail in the woods with thousands of bright yellow daffodils.

A short walk through the woods will take you to an unusual flat hill top, used by the Shakers for outdoor worship.