The Santa Ysabel Preserve near Julian is one of my favorite places to hike. From the parking lot, you have to walk through a herd of cows lazing about and then over a small creek and uphill a bit to reach a large open plateau.
From here, you are surrounded by the Cuyamaca mountain range. Great bird watching here, we saw a large golden eagle sitting in a tree.
Tip: Don't attempt this hike in the summer unless you love heat. Fall, winter and early spring are the best time of year.