We love walking dogs in Watertown. Riverfront Park and Braille Trail. The location is clean, beautiful, quiet and has easy parking. It's a mile long and runs along the Charles river. They even have a trail that people with sight impairments can follow!
Dog walker covering the Watertown, MA area
Another okay spot if your fur baby does not get scared around a lot of traffic is the Charles River Greenway in Watertown.