We came to see the largest volcano - Santa Margarida. A small Romanesque chapel in the crater was built to protect the people against eruptions.
A large map of the park can be downloaded here.
Getting there: parking coordinates N 42 08.885 E 2 32.626. Volcanoes are located near the city of Olot, where you can easily get from Girona, Barcelona and other cities, the bus schedule is here http://www.teisa-bus.com. Some volcanoes located in the city, but the most interesting are in 7 kilometers. You can get there by bus from Olot (go to the Santa Pau stop, schedule on the same website), on foot or by taxi.