About 150,000 years ago, a much larger explosive eruption occurred, probably of Volcanic Explosivity Index 5. It created the Las Cañadas caldera, a large caldera at about 2,000 m above sea level, around from east to west and from north to south. At Guajara, on the south side of the structure, the internal walls rise as almost sheer cliffs from . The summit of Teide itself, and its sister stratovolcano Pico Viejo (), are both situated in the northern half of the caldera and are derived from eruptions later than this prehistoric explosion.