St Marys Mill is on an un-named road just off the A419 at St Marys, Chalford. If you come through St Marys, Chalford towards Stroud, then you take the second small road on the left after the second Hyde turning.  This road is single track, and you come to a gated railway crossing, you will need to get out of your car and press the bell, the level crossing personnel will come and open the gates for you. Do not cross until  both gates are open.