You step out of the minivan to humid air, the scent of wet limestone and green leaves, and the distant roar of water. A short scramble brings you to the Blue Hole: a cluster of jade pools and narrow sinkholes that dare you to jump, swing from ropes and slip into a cool cavern mouth. Later the rainforest closes in around a bamboo raft gliding down the White River while a guide steers with an upright pole toward sunlit breaks where the river opens to the sea. The day ends with the ascending terraces of Dunn's River, where hands and feet find purchase on slick basalt and travertine as waterfalls pour beside you.