This park consists of the volcanic edifice and its very steep sides, which are mostly covered in montane rain forest. It is a stratovolcano 3340 m high with three craters. On its flanks there are several lava flows, one of which passed close to the town of Turrialba. The last eruption occurred in 1864-66 and nowadays there is solfataric activity. The access road that starts in Pastora de Santa Cruz, although grit-covered, is very steep in the upper part and so four-wheeled drive vehicles are required.