Section 2. If buildings or fences have been erected and continued for more than twenty years, fronting upon or against a highway, town way, private way, training field, burying place, landing place, street, lane or alley, or other land appropriated for the general use or convenience of the inhabitants of the commonwealth, or of a county, city, town or parish, and from the length of time or otherwise the boundaries thereof are not known and cannot be made certain by the records or by monuments, such buildings or fences shall be taken to be the true boundaries thereof.
Structure Massachusetts General Laws
Part I - Administration of the Government
Title XIV - Public Ways and Works
Chapter 86 - Boundaries of Highways and Other Public Places, and Encroachments Thereon
Section 1 - Erection of Monuments
Section 2 - Buildings or Fences as Boundaries
Section 3 - Encroachment on Public Ways
Section 4 - Removal of Encroachments
Section 5 - Removal of Gates, Rails, Bars or Fences Upon or Across Ways
Section 6 - Barbed Wire Fences
Section 7 - Removal of Unused Poles, Structures, Etc. From Public Ways