This swimming hole lies just a few blocks from the quaint town square. A low dam on the South Fork of the San Gabriel River forms a wide, deep natural pool, which locals say has never gone dry.
The south bank slopes gently into the clear water, while the north rises in limestone cliffs several stories high and carved by past floodwaters into curving overhangs. Jumping from them may seem like a good idea, but doing so could get you in legal trouble. Instead, soak up the sun from the dam, then cool off in the water amid laid-back folks in floats, tubes, and even canoes. Check out the natural bottom with a mask and snorkel. Drop a fishing line into the Hole, which is stocked with trout in the winter. Blue Hole Park also has a hike-and-bike trail that connects over a pedestrian bridge to San Gabriel Park, where the North and South forks of the river come together. From there, the trail follows the North San Gabriel all the way to Lake Georgetown.
Blue Hole is at W. Second and Rock streets, Georgetown, 512/930-3595. Open year-round; call for hours. Free admission. No lifeguard.