At 12-hectare Senda Verde, there's a new concept: humans are 'caged' while most of the 200-plus monkeys run free. This protects people and monkeys alike (adult monkeys can be aggressive, and sick humans can infect their simian cousins). Toucans, caimans, Andean bears, ocelots and margays are among the other wild residents. There’s a nice buffet-style restaurant on-site. Located 500m north of Yolosa (B$40 taxi or B$10 minibus from Coroico).
The refuge provides a sanctuary for animals that have been rescued from illegal traffickers. Reservations are required. You can stay overnight, or simply come for an hour-long tour. Volunteering is possible (two-week minimum) for B$1370 per week, including three meals.