Planning trip for 10/19-25 which gives us 5 full days. Planning on renting car once we get to La Fortuna. Can we pay the entrance fee to park and do exploring on our own like water falls hot springs and hanging bridges? We plan on booking white water rafting and zip lines and going to animal refuge for tour and volunteering. Love taking pictures. We are 2 ladies 50 and 63 old in reasonably good health. What else can we do on our own without paying a whole lot.