We decided to cut the drive home in half with a stop at the Caverns of Sonora, a National Natural Landmark about 8 miles west of Sonora, Texas. There, we descended 155 feet into the damp cave on a guided tour through over two miles of passageways. The "show cave" was discovered at the turn of the 20th Century and opened to the public in 1960. On our hour and a half hike underground, we admired an impressive combination of live stalagmites, stalactites and helictites throughout a maze of dripping formations. Go there. It's spectacular.