Puerto Princesa Subterranean River National Park Management (PPSRNP) has set a carrying capacity for the Underground River. All persons are strictly required to secure an entry permit from the Underground River Booking Office before entering the Puerto Princesa Subterranean River National Park. Visitors are required to present valid identification cards and register individually prior to the tour, to ensure park admission.Please contact your hotel or resort directly (for specific instructions and arrangements prior to arrival at Puerto Princesa.