Trek to the Lost City (Ciudad Perdida)

Maya city in the Chiapas jungle with the tomb of King Pakal, howler monkeys in the trees and morning mist on the temples.

River cave of Maya skeletons and artefacts.

The Osa Peninsula park National Geographic called the most biologically intense place on Earth — tapirs, scarlet macaws and all four Costa Rican monkeys.

Two-week trek up the Baltoro Glacier to the foot of the world’s second-highest peak.

Climb the vast flat-topped tepui.

Saharan rock art and sand seas.

Sandstone arches and rock art in the Sahara.

The "museum without walls": grassy royal burial mounds, the Cheomseongdae observatory and Silla-dynasty treasures across the town.