Explore The north coast and karst country The north coast Karst country Share Head inland to the Bosque Estatal de Guajataca and you start to penetrate karst country, the forest characterized by giant sinkholes and oval-shaped hills covered with a thick carpet of trees. Unlike many of the island’s sadly under-used forest reserves, this one is well organized, with a network of 46 short, interlinked trails making it one of the best for hikers. Like all state forests in Puerto Rico, entry is free. The information centre (t787/724-3724) is 9km south of PR-2 on PR-446, in the heart of the forest: for the last 2km after the junction with PR-476 the road narrows to a single track. The centre supplies basic trail maps and information, and is usually open Monday to Saturday 7.30am to 4pm, though the rangers occasionally step out for short periods. The campground is along Vereda 9 (trail 9), a short walk from the information centre – you’ll need the usual permit from the DRNA to camp here ($5). The most popular and accessible trail is the Vereda Interpretiva (3.2km), an interpretive trail incorporating parts of Vereda 1 (2.6km) and others, which can be hiked at leisure in an hour and starts near the information centre – grab an English leaflet here pointing out all the main flora and fauna along the way. You’ll pass through groves of pino Hondureño (Caribbean pine), majó (blue mahoe), moralón and María trees and see bunches of white scented flowers sprouting from cupey trees in the summer, but to hear one of the 45 species of birds in the forest, get here early. Make sure you make the short detour to the Torre de Observación (400m from the start), providing magnificent views of haunting karst formations, before continuing onto the Cueva del Viento (2.5km and around 40min). The entrance to the cave itself is partially blocked by wire mesh and a staircase now takes you down into the cavern, along with several vines and hefty tree roots that reach right into the cave. If you have a flashlight, you can explore the large boreholes that lead off left and right: the latter contains spectacular dry limestone formations and flowstone walls, ending in around 120 metres.