Costa Rica has restored visitor capacity at the Sirena Biological Station in Corcovado National Park, allowing as many as 366 people per day to enter one of the country’s most important wildlife destinations after months of restrictions linked to problems with its wastewater treatment system.
The new limit took effect on September 17 and represents a substantial increase from the 225-person daily capacity established in July, when authorities were still working to address sanitary problems at the remote station on the Osa Peninsula. Under the new arrangement, 230 spaces are available for day visitors and another 105 for people staying overnight at Sirena, while 16 spaces are reserved for the local permit holder and 15 for the Osa Conservation Area administration.
Costa Rica’s National System of Conservation Areas (SINAC), said the higher capacity was approved after the park complied with health requirements and carried out work to restore the wastewater treatment system, which had become a major concern earlier this year.
The problems at Sirena came to wider public attention after inspections found serious shortcomings in the treatment system, including inadequate maintenance and difficulties handling the amount of wastewater produced when the station was operating with large numbers of visitors.
At one point, reports documented untreated waste entering a waterway within Corcovado, prompting authorities to reduce the number of tourists allowed at Sirena while repairs and other corrective measures were carried out. The restrictions quickly became an important issue for tourism businesses in the Osa Peninsula, where guides, boat operators, hotels and restaurants depend heavily on visitors traveling into Corcovado, particularly those hoping to reach Sirena.
Sirena sits in the center of the national park and is one of the best-known places in Costa Rica for seeing wildlife, including tapirs, monkeys, scarlet macaws, peccaries and, on rare occasions, large cats. Restoring the higher visitor limit therefore gives tourism operators significantly more space to work with once Sirena is fully open again, although travelers planning a trip in the immediate future should be aware of an important exception.
Sirena will remain closed to tourists during October as part of the park’s regular maintenance period and because October is typically one of the wettest months of the year on the Osa Peninsula. The El Tigre and Los Patos sectors will also close during October, while San Pedrillo and La Leona will remain available to visitors.
Outside of October, the current daily limits for the other sectors of Corcovado remain at 120 visitors for San Pedrillo and 80 each for La Leona, Los Patos and El Tigre. The return to 366 visitors at Sirena does not completely end questions surrounding how tourism is being managed inside Corcovado.
The Environment Ministry has also asked Costa Rica’s Constitutional Chamber for additional time to comply fully with an earlier court ruling requiring authorities to provide scientific and technical justification showing that visitor levels will not harm the park’s ecosystems. The latest resolution restoring Sirena’s capacity refers to visitor-management studies and current sanitary permits, while SINAC says the wastewater treatment system has been restored following work involving authorities, communities and tourism organizations.
However, questions remain over the technical documentation supporting the higher limit, particularly because earlier restrictions had specifically tied increases in overnight visitors to proof that the wastewater system could safely handle the additional load. That issue is likely to remain important because Corcovado faces a difficult balance between protecting one of Costa Rica’s richest natural areas and supporting a tourism economy that depends heavily on access to the park.
Corcovado received roughly 115,000 visitors in 2025, making it both a major conservation area and an important economic engine for communities across the Osa Peninsula. For travelers, the immediate change is straightforward: when Sirena is open, considerably more people can once again visit or stay overnight at the station, but anyone planning an October trip will need to use one of the areas that remains open or schedule a Sirena visit for another month.
