The youngest volcano in Central America.

Medicinal spa created with the discharge from a geothermal energy plant.

Natural cathedral designed by Italian artist Giuliano Mauri.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

These fantastically named natural pools look like something out of a Scottish myth.

One man spent 10 years building a spectacular section of road because no one else would.

Home to the world's oldest functioning orrery.

Host to the annual Festival of the Snakes.

The central mosque of this Mali town is entirely built from mud.

An exquisite tunnel of cascading flowers.

Sleep snuggled in a sphere suspended atop the forest canopy of Vancouver Island.

A botanically themed auditorium blooms within the world’s last operating double-decker theater.

Mutant vegetables, transgenic mosquitos, and atomic rodents span the walls of this one-of-a-kind museum.

The world's second largest salt mine, said to have been discovered by Alexander the Great's horse.

Dr. Farid Mattar's Monument of Peace.

An ancient knight and a symbol of the city's freedom.

A full figure 4th century incorruptible saint lies in a glass coffin in Croatia.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

Longest fortress system anywhere in Europe.

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

Humble beginnings for one of the world's most famous scientists.