Secret Valley Loop is a 6 mile loop trail located near Walnut Creek, CA that features beautiful wild flowers. The trail is rated as moderate offers a number of activity options. Horses are also able to use this trail.
This trail has numerous vistas of Mt. Diablo, much of the East Bay, and up into Napa Valley. Down in Secret Valley the trail gives a solid sense of what the early explorers and settlers experienced in this part of the state. One absolutely gets the feeling of traveling down one of the old stage roads. Portions of the trail are open to equestrian and mountain bikers.
I loved this hike. Me and 2 friends did it today in about 4 hours, taking our time and enjoying the views. The views of the bay are amazing and the hike isn't overly hard. There are some good uphill portions, but there are plenty of level and downhill portions too. We probably added an extra 30-45 minutes by missing the turnaround point and walking about a half mile too far. This hike should take about 2-3 hours depending on your hiking level. I move about 2mph, stopping for breaks every mile or so, stopping for pictures, just enjoying the hike. Overall a nice half day hike, great views, and a nice variety of open wide paths along the ridge, mixed with narrow dirt paths under oak trees.