Denver's major transit hub. Not only would it be helpful to familiarize yourself with navigating through here into the mountains, it also has a lot of great restaurants inside or around the immediate area. Overall a very fun spot. Highlights: Ultreia Milk Market Coors Field
Keystone is a nearby fun mountain town with the largest natural frozen lake in Colorado to go ice skating.
A natural rock formation converted into an outdoor amphitheater. In March there likely won't be any concerts, but is open and free to the public to hike and work out during the day. Not very easy to get to without a car, but worth it if you happen to drive.