Old Tunnel State Park is a popular destination in the Texas Hill Country for nature enthusiasts and bat enthusiasts. It was established in 2012 and is located in Fredericksburg, Texas. The park is situated on the site of an abandoned railroad tunnel that was used in the late 1800s and early 1900s.

One of the main attractions at Old Tunnel State Park is the bat colony that resides in the tunnel. Between May and October, visitors can watch as thousands of Mexican free-tailed bats emerge from the tunnel at dusk to hunt for insects. The park offers guided tours to view the bat emergence, and visitors are encouraged to bring blankets and chairs to watch the spectacle.

In addition to the bat colony, Old Tunnel State Park offers hiking trails, picnic areas, and a visitor center that showcases the history of the area. The park is also home to a diverse range of wildlife, including deer, armadillos, and a variety of bird species.

The best time to visit Old Tunnel State Park is during the summer months when the bat colony is most active. Visitors should be aware that the park is closed during the winter months and can experience occasional closures due to inclement weather.

Overall, Old Tunnel State Park is a unique and fascinating destination in the Texas Hill Country that offers a wide range of activities for visitors of all ages.