The Sarapiquí Association for Forests and Wildlife has identified the Sardinal Hills, The Arrepentidos Hills and the more than two square kilometers area of wetlands connecting the two as an ideal site for preservation because of its high ecological value and unsuitability for conventional development. The area also has the natural infrastructure necessary for a regional nature tourism project. The hills-wetlands complex is a unique ecosystem in Costa Rica and covers multiple life zones extremely rich in biodiversity. At their southern end, the Sardinal Hills join the three private reserves in Chilamate and are thus easily accessed through Chilamate. The Arrepentidos Hills come down to within a few meters of the road to the north of Puerto Viejo, and on their southern side, come within approximately 200 meters of the northernmost part of La Selva. The Arrepentidos Hills are easily accessible from the main street in Puerto Viejo, and thus would allow the hotels in Puerto Viejo to provide forest access to their guests.
The three private reserves in Chilamate are separated from the Holbrook reserve only by the road and a river. Ideally, the Holbrook reserve would be extended 1.7 kilometers to the southeast to connect it to the Braulio Carrillo National Park extension, creating a biological corridor between the Sardinal-Arrepentidos Hills-wetlands complex and the national park. This connection would also conceivably be made between the La Selva property and the Arrepentidos Hills. This area could then be included as another vital link in the greater Meso-American Biological Corridor mentioned earlier. The Sardinal-Arrepentidos Hills-wetlands complex is one of the very few intact, ``healthy'' areas left north of the road that could be linked to the Meso-American Biological Corridor.
The areas proposed for inclusion in this phase of the project are all either rugged hills or wetlands, not suitable for agricultural, industrial or residential developments. These areas are highlighted in pink or blue on the enclosed map B.