The Sudbury Area boasts several excellent squash venues. The following lists some of these and contains directions to the club in question.

Sudbury Family YMCA

The Sudbury YMCA has four international courts, three glass back and one closed back. The facility also offers an enhanced change room for adults complete with towel service.
Map and Directions

Champions Sports Bar

Champions Sports Bar boasts three international courts with an excellent viewing gallery. The facility has no towel service so you should make sure you bring your own.
Map and Directions From YMCA

Howard Armstrong Recreation Center

The HARC is located just north of Sudbury in Valley East. The center boasts (no pun intended) 4 glass back singles courts. The facility includes separate adult change room facilities and a large pool.
Map and Directions From YMCA