The Larsen Audubon Sanctuary on Burr Rd in Fairfield, CT. is open to the public, sunup to sundown 7 days a week.
For Fairfield residents, it's free to explore (and to be quite honest, everyone else, even though a $1 donation is requested).
This is excellent bird watching property as well, so bring some binoculars!
There are also cages where the Audubon Society rehabs injured birds of prey.
Well worth the visit when it is open.