Wildcat Mountain has some of the best running trails within an hours radius of Norwalk and possibly some of the best in the state! The only problem with the trails is horses are allowed on several of them. If you want to get any distance in you will either need to run smaller loops or run the horse trails. On the plus side the views on some of the horse trails are amazing!
The trails vary between single track and double. They offer everything you're looking for; switchbacks, climbs, flats and some of the most difficult trails around. A few more bathrooms would be nice but with all the woods it's not necessary.
Wildcat Mountain is 13 miles from Norwalk.