28. Channel Indiana Jones
Texas has plenty of amazing caves, some of which lie just west of the small city of Sonora (which, FYI, is about halfway between San Antonio and Big Bend). Appropriately named the Caverns of Sonora, the massive cave was carved into Cretaceous-period limestone about 1-1.5 million years ago. Today it boasts one of the heaviest collections of calcite crystal formations, most especially helictites, in the world. Make sure to check out the “butterfly,” where two fishtail helictites share the same attachment point, and the "snake pit," where the formations are so densely packed, you’ll soon be Indiana Jonesing to get out.
29. See the best star show in the state
The McDonald Observatory in Davis Mountains State Park legit hosts “Star Parties,” where you can look through a bunch of badass telescopes (including the biggest in Texas) to see night sky constellation tours and views of celestial objects. As with any good party, you need to RSVP to attend, but if you find yourself without reservations, the park’s dark, open skies are plenty good for catching views.