Okay, it's not exactly a getaway hike, and it lacks the pure allure of a caving experience, but it is still too good to pass up. There used to even be an element of hard exercise involved, but the current regulations pretty well eliminate that element; you can walk the 750' down into the cave, but the trail is now one way only... you are not allowed to hike back up! The only allowed exit is on the elevator. I was told by one of the docents that it is possible to ask for a permit to walk out, but that may or may not be given... may be worth asking for just to see if it is your lucky day.
You can augment the workout by taking the King's Palace guided tour, which will add a nice bit of hiking with some uphill, and another mile can be added by doing the self guided tour of the Big Room. That one is a must...
I found that by being at the doors when they opened for the Natural Entrance (8:30am) that I was able to make my way down through the switchbacks to the cave bottom having both the switchbacks and the Big Room all to myself. That makes for a much nicer experience and is worth the effort. The switchbacks leading steeply down from the Natural Entrance comprises what may well be the most interesting set in the world... certainly the most unique.
Of course, in season there is the famous evening bat flight spectacle... early spring through October. If you are here late in the day make sure you catch this event. You can call 575-785-3012 to check on the status of the event.
The cave offers a very nice respite from hot or inclement weather... a nice steady mid 50's and 90% humidity. As long as you're moving around it is very comfortable, and wind chill factor is at a minimum, but take along a light jacket for sitting around. You'll be glad you did. You can take a break and dine down in the bottom of the cavern, or enjoy a bit more extensive menu up above in the Visitors Center.
There are extensive displays both on the approach road to the cave, and at the cavern visitor center. Additionally, if open, there is a scenic mesa loop drive, and a variety of hiking adventure potentials in the area. Not only will your annual National Parks pass get you into the park, it is all you need to access the cave. There are extra charges for some of the guided tours, and there are other caves available to explore under permit or as ranger guided adventures. Check out their website: nps.gov/cave or call them at 575-785-2232.
A great combined trip will include the Cave, Guadalupe Peak (highest point in Texas) and Mckittrick Canyon... a great bit of contrasting hiking.
Note: there is no camping within the park boundaries. Whites City has motel and RV facility, and there are numerous camping opportunities within the adjacent Guadalupe mountains.
There is gas and grocery in Whites City, but much cheaper to pick up supply in Carlsbad.
So, ignore the crowds, or better yet, get there early enough to avoid them... and Enjoy!