If you're looking for something to do on the way to or from the airport, you'll probably pass right by Rocky Mountain Arsenal! Enjoy some short natural trails by foot or get up-close views of bison and prairie dogs by car on the nature drive. If you go, you'll probably see Julie making heart eyes at the bison and Collin standing in the same spot for ~2 hrs looking for owls.
If you're in the Cheeseman Park area, stop by the Denver Botanic Gardens. It's small but mighty! If you go, you'll see Julie in the tropical conservatory and you won't see Collin because he'll be a few blocks over working in his own garden that is probably inundated with zucchini.
A Colorado classic! There are some hiking trails in the connecting park with great views and, of course, you can stop by to see the natural amphitheater. If you go, you'll probably see Julie enjoying live music and Collin watching the swallows that live in the rock.
Catch a show at Julie's work place! Not to literally market on my own wedding website, but English and Somewhere–two of the shows I'm most excited for in our 25/26 season–will be playing at this time. If you go, you'll probably find Julie working and Collin falling asleep to The Other Josh Cohen.