At the end of a challenging 43km road out of Ojos Negros (east of Ensenada), Parque Nacional Constitución de 1857 has beautiful conifers, fields of wildflowers and a sometimes-dry lake, Laguna Hanson, at an altitude of 1200m. Cabañas (cabins; M$1100) or campsites (included with M$72 park fee) are available (686-554-44-04, 8am to 3pm Monday to Friday); the water may be contaminated so bring your own.
It’s a sublime spot for mountain biking, hiking or just getting away from it all, as long as everyone else isn’t getting away at the same time – in peak holiday times it can be busy, but it’s a beautiful spot any time of year. The park is also accessible by a steeper road east of Km 55.2, 16km southeast of the Ojos Negros junction.