What to do in Denver?

[schock77]

Things have been stressful (house not selling, new house almost done, dog is really sick- I'm a bad country song really!) I go back to work (and hope to close on my new house too) on August 16. So, the hubby decided to take off the week before I go back to work so we could have a getaway. We needed to do something cheap, but wanted to get away from here too. We love the mountains, so he picked Denver...
The kids are staying with grandma, and again, we need to be somewhat cheap... any ideas are appreciated!