Lake Lagunitas is at the top of one of the mountain bike trails I occasionally ride at the weekends. The trail works its way around the edge of the lake. It's a beautiful place at the best of times, but if you catch it at the right time of day, it's breathtaking.
This is taken on Lucas Valley road, a few miles from Skywalker Ranch. The valley ahead works it's way down towards the north end of San Rafael and Terra Linda. As I took this picture, I actually had my back to this thing...
This is Big Rock. So called because it's a big rock. George Lucas owns it. The road here is pretty much the highest point on a 27 mile road circuit that I ride. According to the funky GPS device in my watch, the climb up to this point puts me at about 630 feet above the level where my house is.
This is the data that my watch spits out. The top is GPS location data overlaid on a map, and the graph at the bottom is speed (blue) mapped against elevation (grey)