Lago Dos Bocas (Carr. 123, north of Utuado, 787/894-3505) is a large artificial mountain lake perfect for kayaking and fishing for sunfish, largemouth bass, catfish, and tilapia. Boats are available from the municipal dock to take visitors to lakefront restaurants on weekends only.
Expediciones Palenque (787-823/4354, 787/306-4382, info [at] expedicionespalenque [dot] com, www.expedicionespalenque.com [1]) is an adventure-tour operator that takes nature lovers hiking, rappelling, and body-rafting along the Tanamá River. Sights include Cueva del Arco (Arch Cave) and Tunnel Cave. A daylong tour is $90 per person.
Links:
[1] http://www.expedicionespalenque.com