|San Diego is not especially known for its hiking trails, but is a fine city for the hiking enthusiast if he or she is willing to explore the options on his or her own. With the folded terrain characterizing the area, there are "secret" canyon hikes literally everywhere.
There are plenty of local, intimate canyon trails riddled around the entire city, as well as some non-spectacular but quite decent mountain trails, miles of superior beach walking, long boardwalks and bayside paths. The nearby Anza Borrego Desert has wonderful desert hiking and camping, as well, if you are willing to drive a couple of hours.
San Diego's two outdoorsy parks - Cabrillo National Monument and Torrey Pines State Park - have some shorter trails. Both have their trails on bluffs overlooking the ocean, which is a bonus. Absolutely check out Torrey Pines. The trails are short (1-3 miles for most) but the views are outstanding.
Most of San Diego's hikes are tucked away. There are trails in Julian, the Laguna Mountains, Cuyamaca Park, Anza Borrego desert, Torrey Pines State Park, Palomar Observatory Mountain, Penasquitos Canyon and many gorgeous coastal, mountain and desert locales. There are also swimming holes and waterfalls to explore.
Here are some resources for backpacking and hiking in and around San Diego:
La Jolla Shores to Torrey Pines Beach Trails
There are only a few places along the Southern California coastline where a person can hike for miles in a single direction and not catch sight of a highway, railroad tracks, powerlines, houses, or ot...
Beach Trail/ Broken Hill Trail Loop
This hike will take you to the very brink of the Pacific, passing through scattered Torrey pines (one of earth?s rarest species of trees), and past two magnificent viewpoints on the 350-foot sandstone...
One Hundred Hikes in Yosemite - Everything you've ever wanted to know about the history?human and natural?of Yosemite, with detailed info on 100 hikes to boot. This is the entire text of the book Yosemite National Park: A Natural-History Guide to Yosemite and Its Trails, by Jeffrey Schaffer (Wilderness Press).
Complete National Parks Guide
National Scenic Trails
Regional Hiking Guide