Before getting a ticket you should choose a route. La Fortuna is located at the base of the Arenal Volcano which is part of San Carlos in the province of Alajuela.
-Coming from San Jose or Juan Santa Maria Airport; you can choose route 141 by Ciudad Quesada, taking a bus from San Jose at Barrio Mexico, 12th Avenue, 9th Street, The old Puntarenas bus terminal.
In the mornings can take the direct bus to La Fortuna at 6:15 am , 8:40 and 11:30 am or each hour take the bus from San Jose to Ciudad Quesada and then in Ciudad Quesada in the same bus station take the bus to La Fortuna.
The other option is using route 702 by San Ramon,first you must take a bus San Jose-San Ramon at Puntarenas Bus Station and then San Ramon-La Fortuna.
There are also alternative routes that lead through towns rich in art and culture such as Grecia and Sarchi or roads that cross mountains and volcanoes such as the route through Vara Blanca, however those routes are recommended only with a rented car.