Cuyamaca Peak is located in Cuyamaca Rancho State Park. At 6512 feet, it is the highest peak in the park, and the second highest in San Diego county, behind Hot Springs Mountain in the Anza Borrego Desert. The quickest route to the top is by parking in the Paso Picacho Campground day parking lot off of Highway 79, for a fee of $6. There are a few ways to the top, but the most direct is to walk southwest through campground, looking for the Lookout Fire Road. There should be sign somewhere, you just have to use common sense and look around. From there it is a straight shot to the top. Between 3 and 3.5 miles one way, and it is pretty steep, so your legs will get a good workout.
Since the 2003 Cedar Fire most of the tree cover is gone, so it is mostly a sunny hike, so be sure to bring plenty of water and sunscreen.