Barr Lake State Park. The 9-mile, multi-use Lake Perimeter Trail at Barr Lake State Park (about 24 miles northeast of Denver) circles the lake and passes by several wildlife viewing stations and the park's wildlife refuge. More than 350 species of birds have been spotted in the park, including bald eagles. 13401 Picadilly Rd., Brighton, Colorado, 80603. parks.state.co.us/Parks/barrlake. $7 for a day pass.
Green Mountain. Part of Jefferson County Open Space and a piece of William Frederick Hayden Park (City of Lakewood), Green Mountain is the first named foothill as you head west from Denver toward the mountains. The easy, mostly exposed trails here afford panoramic views of downtown Denver, Table Mesa, Pikes Peak, and the Continental Divide from the top (895 feet in elevation gain). There are multiple trails from several trailheads, including a 6½-mile loop and a 3-mile loop. You must share the experience with bikers and dogs (as well as other critters). Lakewood, Colorado, 80465. www.lakewood.org/HaydenPark. Open daily 5 am--10 pm.
Mount Falcon Park. Looking down on Denver and across at Red Rocks, this park is amazingly tranquil, laced with meadows and streams, and shaded by conifers. The trails are well marked. Aurora, Colorado, 80465. www.jeffco.us/open-space/parks/mount-falcon-park.
Red Rocks Park and Amphitheatre. Fifteen miles southwest of Denver, Red Rocks Park and Amphitheatre is a breathtaking wonderland of vaulting oxblood-and-cinnamon-color sandstone spires. The outdoor music stage is in a natural 9,000-seat amphitheater (with perfect acoustics, as only nature could have designed). Visit even when there's no show. The 5-mile scenic drive offers a glorious glimpse of the 868 acres of sandstone, and there are picnic and parking areas along the way for photos and a rest. If you're feeling particularly spunky, follow the locals' lead and run the steps for a real workout. The Trading Post loop hiking trail, at 6,280 feet, is 1½ miles long and quite narrow with drop-offs and steep grades. 17598 W. Alameda Pkwy., Morrison, Colorado, 80465. www.redrocksonline.com. Open daily (non-show days) one hr before sunrise to one hr after sunset.
Roxborough State Park. An easy, wheelchair-accessible 2-mile loop trail in the park goes through rugged rock formations; there are also myriad harder hikes that offer striking vistas and a unique look at metropolitan Denver and the plains. Littleton, Colorado, 80125. www.parks.state.co.us/parks/roxborough. $7 for a day pass.