Las Piedrotas are a large and impressive group of rock formations set in cow pastures in what's called the Valle de las Enigmas about 6km north of town. It's a good place for walking, rock scrambling or ziplining (M$150) between the two largest formations. Most people drive here, but it's an easy and rewarding 2½- to three-hour return walk along a quiet country lane through dark pine forests, past an abandoned old paper mill and up onto a flower-filled plateau.
To reach Las Piedrotas, take Hidalgo westward out of town, keeping to the left and following the signs for Chiquilistlán (and some signs for Las Piedrotas). Once you've cleared the edge of town, carry on straight. A taxi costs around M$150 one way.
