We had purchased some tickets for inner Space caverns which the caverns had donated to Sophie’s Schools silent auction earlier in the summer and they had lain in a drawer with a busy summer of other things going on.
We were very glad that we found them again as it was a nice way to spend a Sunday afternoon! The caves were discovered when they were building the I35 in 1963 and they are a large network of tunnels stretching under the highway. There are three options for tours through the caves and we had purchased the adventure tour which is the basic tour. there are other options for hidden passage tours (which requires a torch) and then a tour of the undiscovered places which requires climbing throuhg small tunnels and crawling in areas. 
Our basic tour was excellent though. Lasted about 1hr and 15 minutes and ran for about 1.5 miles underground. Fascinating look at how the world has changed over the years and there were bones down there from sabre toothed cat to Mammoth which are huge! 
There have been some changes to the caves to help preserve them whilst opening them to tourists and one wall which was erected to help make them less rough was interesting as an artist had painted a bunch of cave painting depicting the animal bones which have been found in the caves over the years. 
You start the tour by walking down a long passage way to get to the main entrance which is a hike if you are not the fittest but not a major difficulty. 
You are not allowed to touch the walls to preserve the integrity of the walls and the tour guide talks you through how the various different types of rock came to be formed over the millenia.
The bottom of the adventure tour has a lovely pool area where water has formed and we get to about 70 ft down and we’re on the opposite side of the highway from the visitors center. 
Funny to think of all the traffic going on above your head whilst you are in the tranquil atmosphere below ground. The guide will also let you experience total darkness which it is difficult to get above the ground and is a little disconcerting. There is a gift shop and little cafe area for afterwards which was pretty reasonable.
We could certainly not go every weekend but we did enjoy the glimpse of pre history Texas. Well worth a visit.
McAllen Family Adventures 