Costa Rica

Costa Rica is where most people should start. A quarter of the country is protected forest, the roads are manageable, the water is drinkable, and you can be inside primary rainforest ninety minutes after landing in San José or Liberia. Howler monkeys are the alarm clock here; nobody warns you how loud they are.

The jungle stays cluster in a few distinct pockets. Uvita and Dominical on the south Pacific coast put rainforest hillsides directly above whale-watching beaches. Monteverde sits in cooler cloud forest at 1,400 meters. Puerto Viejo on the Caribbean side is flatter, hotter and more Afro-Caribbean in feel, with sloths in the beach almonds. The Osa Peninsula is the wild end — half the country's species on one peninsula, generators and 4x4s required.

Treehouses got serious here before almost anywhere else. Expect proper architecture, plunge pools fed by spring water, and open-air showers where hummingbirds interrupt you. December through April is dry season; the green season (May–November) is cheaper, emptier, and rains mostly in the afternoon.