if you're in the "Springs",
here are some thoughts-
unlike the UK or the Continent, things are rather widely spaced.
You should check my estimated, but you're about 2 hours from Georgetown , and id guess a bit more from Antonito, and about 5 hours from Durango.
I know Georgetown well, its a short ride, id say about 45 minutes down and back (or up and back) with stops-mine tour will add another hour-its worth it imho. They were running either a 2-6-2 rod (now gone) , a porter diesel (big) and in the shoulder seasons, a miserable little ex Army industrial diesel switcher. I don't know if the shay is up and about. THE ROW on the old Colorado Central later C and S ROW, and the rebuilt bridge is spectacular. As I mentioned, this is a short ride comparatively. The drive up will take you into the mountains, via Idaho Springs, and some tunnels. Weekend traffic may be something to be avoided, as Colorado has a lot of infra structure work going on, and its a PITA when you add weekend volume. I try never to drive to the mountains on the weekends unless its before 7 am. Mountain trips are the thing here. Also, if I didn't live here, I think I might not like our road signage. Often if you don't already know they way, I think the signs might not always give enough help, especially in the urban corridor through Denver. Tip, google your directions first and get a step by step, or better, get an onboard satellite map with vocal with your rental car. Actually, do both in case you lose satellite.
Georgetown is small and pleasant and 'quaint' -one of my favorites, but that's because it's close to Denver, ie little time and effort. It has tourists, but unless its fourth of July, I have never been there when its too crowded. It also sports Hotel de Paris, a famous old west 'oasis' for the luxury accommodations in the early west, run by Louis DuPuy. What makes it unique is that this was owned by a single family after Dupuy, and was not renovated (much) and offers a great glimpse into authentic period décor and fixtures-tour takes all of forty minutes and is central in town and inexpensive ($5).
In the Springs, you could also ride the cog railway, Manitou and pike peak, on swiss rail busses-yawn...., and tour cave of the winds -a large interesting cave that should be hugely alive given our recent monsoons.
Be mindful of travel time out here. Mountain driving even when dry and clear slow things, even for those of us that drive them regularly.
It's nothing to drive several hours to some locations.
OTOH, a drive will let you see how the Colonials have 'evolved'... There is much to be said for stopping in the small mountain towns, for a burger or Mexican food, ice cream or, sometimes micro breweries, some of which are truly excellent (and this isn't by "US industrial swill" standards) . These areas don't have the populations or traffic to support the larger chain restaurants, so you can get some , sometimes, decent fair and rural flavor.