This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

In Costa Rica's cloud forest, the roots of a woody ficus create a botanical bridge.

Once the foundation for a mansion, these ruins now offer amazing panoramic coastal views.

A church of bones, decorated with 40,000 human skeletons.

This Neolithic passage tomb forms part of a World Heritage Site.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.

The chaotic studio of one of the 20th century's most important artists has been preserved down to the dust.

Petrified footprints of one of the very first vertebrates to walk on land.

This ancient Irish tower could easily have stood in for Rapunzel's prison.

This single room has survived the centuries with almost no deterioration.

A stunning Victorian abbey and walled garden on a lakefront.

Traveling this mountain pass reveals quaint stone buildings, stunning Irish scenery, and a bridge said to grant wishes.

More than 5,000 artifacts donated by the people of the city, plus a room entirely devoted to the band U2.

The oldest public library in Ireland.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The profile of one ill-fated deacon was emblazoned forever on this church window during the Halifax explosion.

Traditional 11th-century outdoor tannery.

Crumbling necropolis set high above Fez.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

A fortified city, home to a remaining population of five families