I recommend riding around city watershed reservoirs. Scenery is great, and usually gets you a steep uphill ride. Go a little downstream from the dam for an even more challenging ride, and maybe some swimming. The dams and bridges provide some great views. As always, be sure and obey the trail rules, if you take your bike off-road. Obey the boating and swimming rules. Protect the watershed. Most of the watershed reservoirs have some great off-road bicycling trails. The ridges make for a challenge. I like PrettyBoy Reservoir so much, it makes me want to take up bow hunting, which is legal there. Watershed protections make for a beautiful pristine environment around the reservoirs. Take the green path. Ride your bicycle out to the reservoirs.