Bay Area Ridge Trail: Boccardo Trail Corridor

Take ~2hours. Beautiful trail with many animals (beware of snakes, though).

This trail is a challenge. All downhill for first half. Then all uphill for rest. Trail was muddy and some landslides had come on top of it. Also walked through a lot of cattle. Gave wide berth to the bulls. Probably not a hike to bring small children, rain, hail, snow, sun, and wind. Very beautiful views.

Absolutely no shade, dry and hot. Decent views, but a complete lack of scenery on the trail. Only company was a handful of bikers. As for a workout, rather strenuous and good workout. 1000+ ft. straight elevation gain with no break until the summit.

We went in July - cloudy day. The trail has great vistas but almost no shade. We did the Boccardo loop - western side is wide and open, switchbacks on the eastern leg make for nice views of Alum Rock canyon. Quite a workout with the 1000+ feet elev gain.

Cool 7 plus mile loop trail up to the top of Alum Rock and back down. Stunning views above the fog. Not a ton of shade so bring sunscreen. Gets very steep in parts along the Memorial section of trail.

see my review of alum rock park in general, but specifically this trail loop is a bit long, dry and exposed for my taste in hiking. mostly hilly pasture land, lots of manure and flies. rough on the knees coming down. watch out for irritated bulls.
this route affords a nice, panoramic view of the the bay from gilroy to san francisco, but in my opinion, better for bike or horseback. (or someone with younger knees than me)