La Caldera Volcano is on the border between Mexico City and Mexico State. It’s especially noticeable on trips south on the Puebla highway. The road itself skirts the volcano’s western flank. But the peak is today among the most plainly visible from Cablebús Line 2, especially as one reaches San Miguel Teotongo.
Today, it’s a protected natural area, and a popular hiking spot. With a distinctive double crater, it’s probably the most recognizable of the string of volcanos that make up the Sierra de Santa Catarina. The double crater resulted from an early explosion caused by water coming into close contact with the molten lava. This likely took place some 60 million years ago.
Today called La Caldera, the Cauldron, the ancient name was Cuexomatl. At 2,400 meters above sea level, it’s not the tallest in the sierra. It is, though, one of the easiest and most rewarding to climb. Hikers will want to beware of snakes and scorpions, both of which inhabit the slopes in some abundance. The volcano is also frequented by birds and rodents.
Circling both craters on foot (trails are reasonably well marked), takes about 90 minutes. Reaching the base of La Caldera from Metro La Paz takes about 25 minutes on foot. Taxis or moto-taxis, widely available outside the Metro will significantly reduce that time.