From I-35 take exit 206 and head west towards Texas State University-San Marcos. After Post Road there is a railroad crossing.  Just after the track turn right onto West Laurel Street.  There is a large sign above the road that says Aquarena Center.  The entrance is across from Bobcat Stadium on the East side of Aquarena Springs Drive.  Continue over the low water bridge until reaching a Y in the road.  Turn left and then take the first drive  on your right into the parking lot. There is a sign at the corner of the building that says "Ticket Kiosk". To purchase Glass Bottom Boat tickets and to get information about the park follow the walkway until you reach the Ticket Kiosk Window on your left at the end of the first building.