Hartford is a small city and one can access small farm towns in minutes. There are no national parks/forests in the area, but the general wilderness is easy to access.
Wickham Park
1329 West Middle Turnpike, Manchester, CT. A privately owned 250 acre park in spanning East Hartford and Manchester, boasting a picturesque landscape with excellent views of the Hartford skyline. It holds many biking and hiking trails, picnic areas, tennis courts, and an aviary. (http://www.wickhampark.org/)There are also several other cities in the area:
Middletown, CT - 15 miles south.
Springfield, MA - 24 miles north.
New Haven, CT -37 miles south.
Providence, RI - 66 miles east.
New York City, NY.
Boston, MA.
Rural Areas:
Pioneer Valley, MA
Berkshire Hills. MA
Vermont