The Cheyenne Mountain Zoo is actually on the side of a mountain (Cheyenne Mountain, if I'm not mistaken, the same mountain that contains NORAD), which makes it a pretty cool zoo. The Denver Zoo might have a larger assortment of animals, but the location makes this zoo fairly unique (and a decently strenuous walk from bottom to top). Of course, I took my D700 with me and gave my 80-400mm telephoto zoom a workout.
Giraffes have quite the eyelashes:
As usual, click through for the other animals, and plenty of slimy giraffe tongue.