The world's seventh-largest coral reef contains an incredible amount of biodiversity.

An engineering wonder at Pillnitz Castle protects a precious 230-year-old flowering shrub.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

A sublime medieval path adorns the marble floor of one of the most beautiful Gothic cathedrals in France.

These ornate arches show how the course of the River Thames has changed.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

The largest medieval water tank on the Iberian Peninsula is preserved beneath the Cáceres Museum.

A living memorial to the trees London lost during the Great Storm of 1987.

Bronze footprints mark the path where a civil rights leader tried to march in peaceful protest before being knocked unconscious.

An unusual ode to the late Irish playwright, complete with a squiggly bust and coffin-shaped bench.

Roses and other fascinating flora fill this garden built to commemorate Britain's immortal Bard.

A strangely curved lamppost stands tall over this avenue in Rotterdam.

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

In a quiet north Chicago neighborhood rests a stunning relic of the golden age of earthenware design.

A beautiful multicolored mound formed by the mineral deposits of the Orenda Spring.

The fire inside this temple has burned for more than 1,500 years.

An ancient impact crater on the outskirts of Pretoria.

Every January 6, young men dive into Spring Bayou in search of a cross and a year's worth of maritime blessings.

Tombstones and enigmatic inscriptions hide within a vault beneath a popular London arts venue.

Buried for centuries, this hidden cellar is all that remains of London's medieval Whitefriars Monastery.

A measuring mishap led to these artificial stone ladies losing their stomachs.

This ruined 15th-century hermitage is steeped in myth and mystery.

Cornish legend says these ancient circles were people turned to stone for playing hurling on a Sunday.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.