Adjoining the superb Villablanca Cloud Forest Hotel & Nature Reserve (tel. 506/2461-3800, www.villablanca-costarica.com), this reserve has three kilometers of manicured, well-signed trails into its cloud-forest reserve.

The hills are covered with thick cloud forest, with the calls of howler monkeys emanating from its shrouded interior. Bird species include bellbirds, trogons, and aracaris. Laurel trees have been planted to lure quetzals. Three species of monkeys abound, and other mammals such as ocelots, jaguars, and jaguarundis are present.

Guided hikes ($26 nonguests; free to hotel guests) are compulsory for call-in visitors, while hotel guests can take self-guided hikes. Don’t miss the night walk!

INBio has a research center here specializing in butterflies; here visitors can view taxonomists studying butterflies and other insects. The tour of the hotel’s organic greenhouses and compost production facility is fascinating. The vivero (hothouse) is especially interesting on a nocturnal tour, when you can spot dozens of frogs.

The reserve is an extension of the 800-hectare Los Ángeles Cloud Forest Reserve & Adventure Park (8 a.m.–4 p.m. daily); it begins at 700 meters’ elevation and tops out at 1,800 meters. (When the clouds clear you can see Volcán Arenal.) Two short trails (1.5 km and 2 km) have wooden walkways with nonslip surfaces. A third, hard-hiking trail (plan on 6–9 hours) descends past waterfalls and natural swimming pools.

A zip-line canopy tour ($42) features 10 treetop platforms; guided horseback rides ($15 per hour) and bird-watching and nature hikes ($24–55) are offered.