Manuel Antonio, Tortuguero, Corcovado, and Arenal are the parks people plan a trip around. Manuel Antonio caps how many people enter each day. Corcovado requires a guide. Tortuguero has no road. Arenal is a view from the base, not a climb. A park day needs the morning.
Manuel Antonio, next to Quepos, is the short Pacific park. The trails, the monkeys, and the beaches are past the gate. Punta Catedral is a forested point, about an hour if the path is not too muddy. Playa Manuel Antonio, inside the gate, is the calmer swim. Playa Espadilla, the public beach outside, can pull. Do not leave food on the sand.
Arenal, at La Fortuna, is the cone you look at. The summit stays closed. The 1968 lava trail is open rock and little shade. The hanging bridges are a separate loop in wet forest, slick after rain. The town waterfall is a long stair to a cold pool, and the same stair back out. The hot springs around the base are built pools and a separate ticket, usually after dark.
Tortuguero is canals, not a highway. You arrive by boat, and most stays are a night. The daytime trip is the canals. The beach is for nesting, not a noon swim. Corcovado, on the Osa Peninsula, is the large lowland forest. Sirena ranger station is inside the park. You reach it with a guide, by boat or a long beach walk. It is not a view from the road.
The others are worth it when you are already next door. Cahuita is a reef you can walk to from town. The water is clearer after a few drier days, not the morning after a hard rain. Marino Ballena, at Uvita, is the whale-tail beach. The sandbar exists only at low tide, and you pay at the ranger hut. Las Baulas, at Playa Grande, is the leatherback beach from about October to March, at night, with a guide. Poás is a steaming acid lake above Alajuela. You look from the rail. You do not walk to the lake.
