Sierra Azul Open Space is one of the biggest parks in the South Bay, and one of my favorite spots in general. The area offers great views of San Jose, and on a super clear day you are able to see the whole Monterey Bay on the other side. The area plays host to hikers, runners, mountain and road bikers. The highest peak in Sierra Azul Opens Space is Mt. Umunhum at 3,486 feet. Road bikers like it because the climb is long and descending is just as long, and the pavement is soft with no potholes (until you get back onto Hicks Road.) Runners and hikers love the 4 mile, 9 mile or 17 mile up and back routes.