Discover cool things to do in San Marcos, starting with water activities at the San Marcos River, popular for tubing, kayaking, and swimming. Visit Wonder World Cave & Park, a unique natural attraction offering cave tours, an anti-gravity house, and a wildlife park. Explore The Wittliff Collections at Texas State University, a cultural treasure featuring Southwestern and Mexican photography and literature. Enjoy retail therapy at the large outlet malls in San Marcos, known for numerous brands and discounts. Lastly, take educational tours at Aquarena Springs, where glass-bottom boat tours provide a view of the underwater life in the San Marcos Springs.