Volcano Popocatepetl has been watched by UFO researchers for years. On of the methods of watching it is the live Internet cams. Several exist for this volcano. I myself have used the cam and caught UFOs there several times and posted two videos. What I'm trying to say is that dozens of videos exist of UFO at this volcano. For UFOs being seen coming and going from the mouth of the volcano there can be only one explanation...they enter a hidden entrance in the volcano that leads them to an underground base.
The mouth of the volcano is perfect for this because no human has ever entered it before. The walls of the crater have a sheer drop of 600 meter to 840 meters high which keep all adventurous people out. One of the few places on Earth that humans don't want to go...except this human. Sure would like to try it out, but those gasses inside are surely deadly.
Question: If someone was bold enough to get the equipment together and enter the mouth of the crater and ascend to its bottom, do you think aliens would open the door to let the person in? SCW