Denver Botanic Gardens - http://www.botanicgardens.org/Denver U.S. Mint - http://www.milehighcity.com/capitol/Tattered Cover Bookstore - http://www.colorado-for-free.com/FreeThi��Brown Palace Hotel - http://www.brownpalace.com/about_the_bro��Dinosaur Ridge - http://www.dinoridge.org/Red Rocks Amphitheatre and music museum - http://www.colorado-for-free.com/FreeThi��Coors Brewery - http://www.colorado-for-free.com/FreeThi��American Mountaineering Center museum - http://www.mountaineeringmuseum.org/National Earthquake Information Center - http://earthquake.usgs.gov/regional/neic��The great thing about this list is that nearly all of these places (except the botanic gardens and the mountaineering museum) can be visited for free.
art museumaquariumzoo16th street malldenver night life is fun (depending on your age)red rocks in an amazing landmark/venue you can walk around it whenever you want depending on the weathercheck the local venues and see if there are any concerts you would be interested in