The Town's official website's page about Menotomy Rocks Park: http://www.town.arlington.ma.us/public_documents/ArlingtonMA_Recreation/maps/menotomy
The Friends of Menotomy Rocks Park (FMRP) were organized in 1993 to advise the Town of Arlington concerning the use, care, and maintenance of the park, and to assist in the preservation and improvement of the land, help keep and improve the fields, pond, plantings, pathways, trees, and other natural features of the park, improve species habitat and assist in the maintenance and provision of facilities furthering recreation and enjoyment of the park. The FMRP also conduct programs to educate the public and to promote the values and ideas upon which open space and community parks depend.
http://www.friendsofmenotomy.org/
Google Map showing the park: