What became of the 1980s efforts of a group of Swedish schoolchildren to save the rainforest? Only this enormous 2300-sq km reserve – the largest private reserve in the country. It's mostly inaccessible to tourists, with the exception of the well-marked 4.5km Sendero Bajo del Tigre, which is actually a series of shorter trails. Make reservations in advance for the popular two-hour night hikes.

At the entrance there’s an education center for children and a fabulous vista over the reserve.

The Estación Biológica San Gerardo, reachable by a rather gnarly 2½-hour trail from Reserva Santa Elena, is managed by BEN and has dorm bunk beds for researchers and students, but you may be able to stay overnight with prior arrangements. In 2020, a new tax will raise rates for hiking and stays by 4%.