The Cheyenne Mountain Zoo isn't the largest you'll ever see, but it is expansive enough, and has a lot of unique things going for it. You'll see, and get up close to, more Giraffes than you thought possible. The meerkat exhibit is excellent. There's a great penguin stop. The environment on the side of super steep Cheyenne Mountain gives the whole place a more natural feel than most city zoos. If you're coming from sea level, you may want to pace yourself as there will be a lot of walking up hill at high altitude.