The grotto where Saint Ignatius of Loyola lived as a hermit for nearly a year.

Perhaps the most spectacular grotto along the Algarve coastline.

An art-filled botanical garden and former dyeworks hiding in plain sight.

Every summer, the Mendenhall River greenbelt comes alive with an explosion of magenta flowers.

A former travertine mine traces the geological history of this unique desert filled with crystalline blue pools.

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

A series of magical limestone formations along the coastline of the country island of Antigua.

In the heart of Luxembourg's "little Switzerland" weaves a breathtaking natural sandstone canyon with a mythological past.

The damming of the Colorado River buried an iconic geologic formation before record-breaking drought brought it back.

At the most northwestern point of the contiguous United States lies a trail leading through an ancient forest to stunning cliff-side vistas and massive oceanside caves.

The writer took refuge in this home in Southern France for the last 17 years of his life.

A medieval military street hidden beneath a charming French fishing village.

The once-dying town of Sheffield, Tasmania has reinvented itself as a village of painted wonders.

Countless expeditions have left Tasmania to explore Antarctica, but this island state has an even deeper connection with the sea.

The world's first cageless zoo is working to save endangered Tasmanian devils.

A 30-acre garden inspired by the principles of modern physics.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A school teacher's massive and terrifying self-built castle.

A sacred lake composed of over 300 separate pools of highly concentrated minerals.

Eastern zen meets Western grit in these four little trees growing out of a rock on Lake Tahoe’s Nevada shore.

A solitary tree has grown up all alone on Lake Wānaka, backdropped by the beautiful Southern Alps.

The half-mile long structure is so impressive, it even shows up on satellite images.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Buildings from the fictional planet of Tatooine still litter the Tunisian desert.