Yesterday CT Joyce and I took the day and explored the Farmington Canal Trail on our bikes. The old canal/railroad trail has been converted to a modern paved trail suitable for walking, riding, roller-blading, and jogging. The nice thing about the rails- or canals-to-trails is there are minimal hills; trains and water tend to like it fairly level. So a full day of biking doesn't get too exhausting.
The trail roughly follows Route 10 from downtown Hamden up into Cheshire, and then there are additional developed areas in Farmington, Simsbury, and nearby towns. The photo below is of the restored Lock 12 on the old canal off of Route 42 in Cheshire.