Corcovado National Park is open to the public and can be visited on day trips and for overnight visits and all Corcovado visitors must be accompanied by certified professional guides. That exactly how we have visited the park.
Right after crossing the Costa Rican border from Panama, we took a taxi to Sierpe, last town near Corcovado accessible by road. From there onwards, we boarded a ferry that took us down the Sierpe river to the Drake Bay. We headed past the Drake bay and spend two nights in a very remote, but beautiful Jaguar Jungle Lodge. The next day we head out to the remote San Pedrillo ranger station with our guide, where we spend most of the day exploring the jungle.