Balmorhea State Park has the largest spring fed pool in the world. It's in West Texas- 2 hours north of Big Bend National Park in the foothills of the Davis Mountains. The pool is feet deep in parts & is great for scuba diving & snorkeling.
Fun website! It shows you all the roadside attractions (as well as food, hotels, etc) along your route - Filter results for whatever interests you #TravelDestinationsUsaCrossCountry