I went on a 20 mile hike here recently with a meetup group. Because the Fairfax open space is large with a lot of criss crossing trails it is a good location to do a long hike, but you can easily do a shorter hike too. There were a number of people on the trail, mostly other hikers but a lot of mountain bikers too. Route Details: Start at the Brown Bridge to Loma Alta Loma Alta via Gunshot Fire Rd to the Top of Loma Alta– 1000 Feet Gain– 3 Miles Loma Alta to Big Rock Ridge– Loss of 400 Feet– 3 Miles Big Rock Ridge to Lucas Valley– 6 Miles(You can see George Lucas’ house) Lucas Valley to Sleepy Hollow– 3 Miles Sleepy Hollow to 680 Trial– 2 Miles 680 Trial to Loma Alta– 2 Miles Loma Alta to Brown Bridge — 1 Miles There are a few higher peaks ~1,400−1,800 ft of elevation gain, giving you some very nice views. Most of the space is standard California hills with a lot of grass and only occasional trees. The 680 trail in particular was very nice. The trail is new, well maintained, covered with trees, and good looking. This particular hike took our group a little over eight hours 9:15 start to 5:30 end with a break for lunch. Even though it took eight hours it didn’t feel like that much time had passed. On the plus side you have a quick hike over to Fairfax and a variety of food options after the hike.