San Marcos lies on I-35 between Austin and San Antonio. The home of two huge Texas attractions, Texas State University and the San Marcos Factory Outlets, San Marcos in 2006 surpassed San Antonio’s Riverwalk to become the #1 tourist destination in the state. However, its main charm lies in its long and rich history, much of which revolves around the beautiful crystal-clear springs which form the headwaters of the San Marcos River. Spanish missions were established here in the 1700’s; but man was here long before that--the massive springs are thought to be the oldest continually inhabited site in the Western Hemisphere. Theme parks Aquarena Springs and Wonder World showcase the geological history of this beautiful area.