>>648538You can fish in the Rio Grande. If you have a passport you can raft it. Tons of hiking, beautiful scenery, lots of interesting geology if you're into that sort of thing. It's one of the darkest places on the planet at night, which is why I mentioned stargazing. Take a telescope and be amazed at the universe in which we live. There is also a very large Texas state park adjacent to BBNP. You can go there and get a few days worth of guided trip on horseback if you're so inclined.
>this cave formation is in BBNP 