The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Roman ruins top white travertine terraces formed by ancient hot springs.

Naturally protected city carved from a rock face.

Mediterranean castle on a tiny Turkish island.

Longest fortress system anywhere in Europe.

Pre-Incan aqueduct amidst a stone forest in Peru.

An indigenous take on European design creates a stunning visual overload.

Experiencing Guatemala's sensory-exploding church is a blunt reminder of European influence.

Death rituals and sacrifice inside a Peruvian megalith.

Volcanically heated hot springs.

These azure waters were thought to lead to the Mayan Underworld.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

Fowl, love and death in Vietnam.

Australia's first opal field led to a mining rush in the 1890s.

This Tang Dynasty behemoth is the biggest Buddha in the world.

Intensely colorful calcite pools in Southern China.

Snow-capped peaks, colorful waterfalls and stunning vistas on the edge of the Himalayas.

A collection of outdoor mystical statues paying homage to indigenous Australians and ecological stewardship.

Clusters of huge boulders in the Australian Outback.

The only pollutant in the clear blue water is sunscreen.

A precariously perched golden rock defies gravity and brings pilgrims from across Myanmar.

Ruins of a German castle on top of a towering stone pillar.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.