Lake Calavera Hiking Trail

On our list of the best activities in San Diego.

Mount Calavera rises out of the preserve as San Diego County's only extinct volcano, a 22-million-year-old plug of hardened lava that a network of use trails climbs from several directions. The formal loop through Calavera Nature Preserve winds past coastal sage scrub and chaparral before reaching the man-made lake below, a reservoir behind a dam where coots, night herons and other coastal birds gather. From the volcano's summit, on a clear day, the view runs from the Pacific to the ridgelines of the Cleveland National Forest. A Solar System Walk of planet cutouts runs along the paved stretch near the dam, and leashed dogs are allowed throughout.