Kennedy-Limeklin Area is a 11.8 mile out and back trail located near Los Gatos, CA. The trail is rated as difficult and primarily used for hiking, walking, and mountain biking.
(This has a happy ending) The trail is rough-hewn (rocks sharp enough to be felt through boots) and wide (rare shade, bring EXTRA water). Summit has one "up & down" after another, which was irritating in both directions. The views are rare. But...
...when you do get a view, it's stunning.
...trail runner I met said if you can dodge the rocks (and are in ridiculous shape), it's a great, solitary run.
...mountains bikers paradise (well, almost - needs more shade).
...horseback riding looks nice (but for the sake of the horses, ensure they're well shod).
This is probably the best trail in the Southbay for preparing for harder hikes like Halfdome or Mt Whitney. A full Kennedy-Limekiln-Priestrock-Kennedy loop will be over 14 miles with more than 3500 cumulative elevation gain. I have done the entire trail along with the interconnected Priestrock and Limekiln trails at different times. I have been doing the Kennedy (till the Priestrock intersection) almost every week since last November (in preparation for a Grand Canyon Rim to River hike and a Halfdome hike I'm planning this May-June). Hoping to incorporate parts of the Kennedy-Limekiln-Priestrock loop in the coming weeks.
These trails include vigorous routes, in my opinion, up to the Sierra Azul ridge overlooking the valley. 'Very satisfying getting to the top like where Kennedy Trail comes from residential Los Gatos (Shannon Valley) meets the Priest Rock Trail from Lexington Reservoir (Alma Bridge Road).
Taking the round trip up Lime Kiln and back to Alma Bridge Road is a vigorous 4+ mile walk. Kennedy up and back from Kennedy Road is a vigorous 7.5 mile walk.
The Lime Kiln trail is all up from Lexington, but meant has shade and is not a fire access trail. It is a nice trail all the way through to the Woods trail intersection.
Kennedy along the ridge has some steep ups and downs.
Priest Rock Trail has very steep ups going to its summit.
Keep hydrated! I am not an intense runner/biker but found myself easily using up three liters of water on a hot day going up and back to Kennedy via a 10 mile LimeKiln/PriestRock/Woods/LimeKiln loop.
Long down hill returns to base can be tough on your knees!