Heliconia Island is located between Las Horquetas and Puerto Viejo de Sarapiqui. From San Jose, take route 32 (to Limon) through national park Braulio Carillo. Coming out of the park, turn left at the big busstation, route 4 (to Puerto Viejo de Sarapiqui). After 22 km you'll see the sign "Heliconia Island" on the right side of the road. Turn left and follow the signs.
From Puerto Viejo de Sarapiqui Follow the road number 4 direction Rio Frio, Limon for about 8 km. After the Castrol gas station ( left hand side ) and the little bridge across the rio Isla Grande is after 500 mts the sign Heliconia Island, on your left hand side near a bus stop. Go onto the unpaved road to the right and follow the signs to the entrance.