At over 20 miles and length and still in the process of being explored, Honey Creek Cave is Texas’s longest cave. So long, in fact, that it passes beneath two counties. For the past 30 years, the cave has been actively explored although it is not open to the public and to get a look inside, you’ll need to find a grotto club planning a trip there. You can still explore the aboveground sights of Honey Creek Cave State Park or head to one of the many other caves in the Hill Country area. The majority of Texas’s caverns and caves can be found in this part of the state, due to the limestone and dolomite terrain that leads to the creation of the area’s typical karst formations.