Las Piedrotas is Tapalpa's signature natural sight: a grassy valley scattered with enormous rounded rocks that look as if they were dropped there by accident. The place is also called Valle de los Enigmas, which suits the strange scale of the boulders.
You can walk here from town if you have time, but most visitors come by car, motorcycle, or horse. Go early or late for softer light and cooler air, and bring shoes that can handle uneven ground.