I went there many years ago (c. 1993?). I liked it because it wasn't so vast and overwhelming that it couldn't be seen comfortably in a day. And no, not like where Chevy Chase looks at the Grand Canyon and says ok, let's go. It didn't seem like a grueling hike or anything but there were some nice formations inside, worth visiting. But as BB says, I don't recall much else being in the area except for Border Patrol. And time your visit so you can see the bats. https://www.youtube.com/watch?v=yybkQEp0hJg