Calling this mountain ‘Old Peak’ is something of a slight misnomer considering it was actually the last of Tenerife’s volcanoes to have erupted on a grand scale. In 1798 its southwestern flank tore open, leaving a 700m gash. Today you can clearly see where fragments of magma shot over 1km into the air and fell pell-mell, while torrents of lava gushed from a secondary, lower wound to congeal on the slopes.
To this day, not a blade of grass or a stain of lichen has returned to the arid slope. The ascent of this peak is overlooked by most in the hurry to stand atop Spain, but those in the know often rate this as more impressive than the climb to the summit of Teide itself, and it’s certainly much less busy (you may actually find yourself alone on the mountain). Pico Viejo also has the added advantage of not requiring any special permits.