I flew into Denver on a Thursday and checked into Hostel Fish before walking to Coors Field for a baseball game. It is a great stadium and worth checking out. There are lots of interesting bars in the area that offer fun experiences/games (cornhole, ping pong, jenga, etc.) and also some craft breweries as well. On the second day I explored the city (16th Street Mall is famous for shopping and food) before going to Golden--a town west of Denver--on Saturday for an incredible hike. The town has the Coors factory in it and they offer tours if that is something you are interested in doing. (There are also rivers running through lots of cities in this part of Colorado and they are really pretty). From Golden I took an Uber to Red Rocks amphitheater for a show. This is the best concert venue I have ever been to and can’t recommend it enough.
I went to Boulder (where CU is) on Sunday for a hike and to explore, and then again on Monday. Boulder is an awesome place and is certainly one of the places to go if you are in this region. That evening I decided to go to Fort Collins and stay in an Airbnb. Fort Collins is also an awesome town and I considered moving there permanently after my trip, though I have yet to do that--maybe one day! There is a nice downtown area with lots of restaurants and shops (also CSU is there) and on the west side of the town is Horsetooth Reservoir at the foot of the Rocky Mountains. There are water activities to do there and also you can go hiking on either side of the reservoir with beautiful sunset views. My first night in Fort Collins I stayed in an Airbnb and had trouble finding a place to stay the second night. I considered going to Cheyenne, Wyoming for Frontier Days (a rodeo) but ultimately decided not to. Instead I bought a sleeping bag and slept under the stars near the reservoir. (Potentially dangerous, so I wouldn't really recommend). I did this for two nights before making it back to Denver for my flight home.