The Guagua Pichincha Volcano had its last eruptive phase between 1999 and 2000; since then the volcanic activity has remained low, with some periods of greater or lesser intensity. The descent to the crater is restricted because of the risks that still exist, especially by volcanic gases and groundwater explosions that are unpredictable, in addition the ever present risk of falling rocks, so THIS TREKKING IS NOT ADVISED TO THE TOURISTS. However, when the volcanic activity is low a few researchers and intrepid explorers continue to descend to the crater bottom.