I went for a quick hike recently at Sugarloaf Open Space in Walnut Creek. This is a great spot just outside of the downtown area. While I will say the space is not very large, it was still nice to get outside and move around. The hills were a bit steep in some areas, so bring a walking stick or make sure to take a break along the way. And it was a bit muddy when I was there, so bring your hiking shoes or a pair of old trainers.
I will also say there was a nice picnic table area and a few benches situated along the trails. Great for a light lunch or a quick snack. Also bring your camera along! Great views of Mt. Diablo off to the East.
And one quick picture from my visit. This spot made me long for a journal to write in, a good book to read, and possible a good glass of wine to watch the sunset.