This medieval sanctuary's tree-framed door looks like a portal to a mythical realm.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

The main gates have been locked since 1745 and will remain so until the Stuart Dynasty returns to the throne.

This Parisian café sticks almost exclusively to an ethos of reuse.

A tribute to the Nirvana frontman hides beneath the bridge that was the singer's beloved hangout spot.

Known as the Sistine Chapel of Egypt, this tomb houses some of the most well-preserved paintings in Egypt.

A unique collection of diving equipment spanning antiquity to the present day.

A magician and his beloved, pampered canine were buried together, within days of each other, due to a tragic twist of fate.

This tower pays homage to a legendary Viking fort established in Massachusetts that never really existed.

A 14th century castle built on the seat of a mighty giant.

One of the last remaining covered bridges in the province of Ontario.

Known as the Royal Palace of the Euganean Hills, this often overlooked castle has been home for multiple noble families over the centuries.

Rare recess caves fill this unbelievably beautiful Ohio park.

A historic holy well hidden near a charming English park.

Perched on a spindly rock spire in a Greek archipelago, this lighthouse would make a perfect wizard's tower.

A spectacular cave and a beguiling lake.

Monasteries on rock pillars, once accessible only by frayed ropes.