Wide, flat trails along Quashnet River in Mashpee (Cape Cod) Mass. A real hidden gem. Very wide, flat trails along the Quashnet River in Mashpee. Lots of little trails to the side. Round trip from Martin Street to Mashpee High School is a nice one hour walk. Great off leash walk. No roads. Everyone you see will have a off leash dog. Terrific year round. Location: Martin St, Mashpee, Ma. Directions: Rt 28 (from Falmouth or Mashee) to Martin Street.