I assume you are going to by air. I have always wanted to check out the airport after reading about some "Conspiracy Theories" about the Denver Airport.
I am not the tin foil hat wearing type, but there sounds like some interesting things to see at the airport:
1. Airport's dedication stone
2. Creepy murals "In Peace and Harmony With Nature", "Children of the World Dream of Peace"
3. Mustang, nicknamed "Blucifer" by conspiracy theorists, this statue is 32 feet tall and 9,000 pounds. Its eyes glow red at all hours of the day and night.
4. White tent tops are meant to resemble the snow-capped peaks of the mountains
5. Walking through those weird tunnels that change colours and sounds
Have a great trip and if you check out the airport let me know if the above is worth checking out or it turns out to be stuff the conspiracy theorists are making a big deal out of nothing.
If you like beer there are lots of microbrewers that offer tours.
https://www.denvermicrobrewtour.com/