Longhorn Cavern State Park, south of Burnet in Burnet County, is 645.62 acres classified as a scenic park in the rugged Hill Country. Longhorn Cavern was acquired in 1932 - 1937 from private owners. It was dedicated a state park in 1932, was opened in 1938 and was dedicated as a natural landmark in 1971.

The cave was first formed when the ground levels of water began to drop. As this downward movement occurred, the water began to dissolve the limestone. This downward drainage continued until great underground stream beds were cut out of solid rock. It is this unusual combination of dissolving and cutting by water that makes Longhorn Cavern one of the most unique caves of the world.

The cave has been used as a shelter since prehistoric times. Among legends about the cave is one that the outlaw Sam Bass hid a $2 million cache of stolen money inside. Confederates made gunpowder in the cave during the Civil War. Legend also says Texas Rangers rescued a kidnapped girl from Indians in the cave.