Pico del Teide
Peaking at an altitude of 3 718m, El Teide is an impressive volcano and the highest point in the whole of Spain's territory. From the cable car station (3 555m), you need a permit to continue the climb on foot (around 30min walk on unstable volcanic terrain, so take comfortable shoes and warm clothing). At the summit, there is a gaping sulphurous crater, almost 25m deep and 50m in diameter. On a clear day, the view takes in almost the whole archipelago.