Beautiful paved walkway alongside the Charles River, mostly shaded with lots of trees and underbrush. You can see on Google maps where the trail is since sometimes it is north of the river and sometimes switches to south of the river. We walked the trail in Waltham but it goes all the way to Boston.

Its paved and long....but not particularly pleasant. You are less than 50 feet from very busy roads most of the way, and the Canadian Geese can be in the way. In the winter, the restrooms are all closed and locked. They do keep it plowed, but on warm days, a lot of water will re-cover the surfaces, and on cold nights, re-freeze. If you live there, its Ok. If you are looking for a good bike trail, look elsewhere.

The trails that line both sides of the Charles River from the estuary at the dam where it flows into the harbor winding all the way up to Waltham was initially created by Frederick Olmstead in the later 1800's as a landscaped promenade in Boston on reclaimed riverside land. Extended and tenaciously preserved over the years to create a unique urban riverside park that is enjoyed by thousands every week. Paved and natural trails with benches and docks, playgrounds and memorials amongst open lawns and wooded spaces allows pleasing changing vistas and environments along the ways. Amenities of the city are never far away, but quiet seclusion can still be found on the busiest of summer days. Biking is the best way to experience it all in total, though a dedicated walker can easily traverse the most of it in a long day. Of course, being ON the river offers it's own unique perspective, from sailing.peapods, Ducktours.and serene lunch cruises, in the wide open, breezy lower basin, through pleasing bridges, or in kayaks and rowing shells up into the winding, wilder upper reaches, narrowing up to the dam beyond Watertown. The justly named Emerald Necklace adorns the cityscape, a worthy, quiet and essential exploration experience of this world city, nothing like it anywhere.

The river paths in Watertown stretch all along the Charles, connecting to those in Cambridge, Brighton and Waltham. The section on the Watertown side of the river from Watertown Square to Waltham has been enhanced with wood walkways suitable for running, walking or biking. For runners, the distances for bridge loops have been all measured, so there are nice river runs ranging from about a mile and a half on up. Stop by the Watertown dam, just outside of Watertown Square, and watch the herons fishing among the hoards of Canada geese and ducks. Oh, all along the river paths, do watch out for poison ivy. There is a lot of it, but avoiding it is easy if you stay on the paths.

I stayed with a friend on California street and it was just across from the Charles river conservation...........i am passionate about trails and walks......set off and found the experience rewarding