Old Tunnel State Park

Old Tunnel State Park is Texas's smallest state park, featuring an abandoned railroad tunnel surrounded by oak and juniper woodlands. Two observation platforms provide viewing areas for exploring the tunnel and the surrounding forest setting.

The tunnel was built in the early 1900s when the San Antonio, Fredericksburg and Northern Railway operated through the Texas Hill Country. The railroad stopped using the line in 1942, after which the tunnel became a natural refuge for wildlife.

The site takes its name from the abandoned railroad tunnel at its heart, drawing visitors interested in learning about the area's rail history. Guided programs help people understand how the railway and local wildlife are connected through the park's educational focus.

The park is open year-round, but the best time to view the bats is from May through October. The lower observation platform requires advance reservations, while the upper platform is available without booking.

During summer months, over three million Mexican free-tailed bats exit the tunnel to hunt insects across central Texas farmlands. This nightly emergence is a rare natural spectacle that occurs at few other locations.

Location: Kendall County

Inception: 2012

Website: https://tpwd.texas.gov/state-parks/old-tunnel

GPS coordinates: 30.10100,-98.82100

Latest update: December 8, 2025 19:56