A floating cat sanctuary on an Amsterdam canal.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

Cat art as far as the eye can see.

A curious collection dedicated to human and animal anatomy and pathology.

Museum preserving torture methods from the past.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

The world's only museum devoted to the wonders of fluorescence.

An enigmatic natural rock formation with a manmade passage cut through the center.

Isaac Newton's former home, where the famous apple tree still stands.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

This romantic, decaying 13th-century ruin on the edge of Sherwood Forest is reputedly one of England's most haunted places.

A domed disco abandoned since the '70s now attracts artists and explorers under its unique roof.

The abandoned tuberculosis sanatorium is said to be one of the most haunted places in Canada.

An unrealized Taoist palace left abandoned in a Houston suburb.

An archaeological treasure trove towers over the valley of Chiavenna.

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

The deserted railroad town had a last gasp as a ghost town attraction before being abandoned for good.

An abandoned 18th century manse looks like something out of an Indiana Jones movie.