If that is Galeana, south of Monterrey, that is where Pozo de Gavilan is. I would not want to be in there in an earthquake.
P.S. I was in Austin yesterday, and tried unsuccessfully to get some cavers to dine with me at Bender Bar & Grill. I am back in Houston now, but hitch-hiked all over west Austin yesterday, and rode several buses, and a Super-Shuttle and eventually ended up at the Travelodge next to the Greyhound bus station. I was on hopefully a high-paying solo mission to convince a rich mental patient hiding out in a motel to come to a rehab center in Houston, but the mission failed. David Locklear