Two separate but nearby North Andover parks, both overlooking lovely Lake Cochichewick. Osgood alone has 200 acres of land, and Weir adds 194 more, so there is lots of room to roam here.
Check the excellent website of the Friends of North Andover Trails for events at these places, and more information.
More Resources:
Osgood at FONAT!
The webpage of the Friends of North Andover Trails
Weir at FONAT!
The webpage of the Friends of North Andover Trails
All Trails for Weir Hill
Recommended trails and map
All Trails for Osgood
Recommended trails and map
The Trustees
The Trustees manage Weir Hill; this is their info page
Weir Hill at Wikipedia!
Weir Hill even has its own Wikipedia page!
Osgood Hill at Wikipedia!
Osgood also has its own Wikipedia page!