Tikal
If you decide to visit Tikal you will need a travel angency that arrange a daily and weekly tours to various parts of Costa Rica. Some destinations, such as Tortuguero, are difficult to get to without the help of an agency, so even if you are very independent, you can consider looking into a tour. Also ask about the vaccinations or medicines that you might need.
Tikal it's muddy, probably will rain all the time and the mosquitos will eat you alive, but you are an adventurer right? ;)
Visitors to San Jose should not miss this enormous national wildlife reserve, home to monkeys, quetzals, jaguars and many other animals. Hiking trails wind through the thick plant growth, over streams and usually past numerous wild animals. Ride the Rain Forest Aerial Tram to view the park from above and see birds and plants not usually encountered at ground level. The park is just 50 minutes from San Jose. Arrange to sleep overnight in a cabin in the park, where Restaurant "Sacramento" offers simple but tasty meals.
