This first one is a church at the top of some stairs. With Chihuahua being a mile high, we were out of breath quite quickly. But we got to the top, and explored the building. Which was quite cool since it was not cordoned off in some weak-floored areas or anything, so we got to explore everywhere we wanted.
Next, we went over to look at some mineshafts, which were quite cool. We dropped a rock down one of them, and stopped hearing it hit the wall after about 9 seconds.