The Duke's Warehouse was built at the end Bridgewater Canal over the River Medlock. It has long since gone. It was first built in 1771, destroyed by fire in 1789 and rebuilt and extended including a fulling mill on the southern bank and cottages on the northern bank. It was destroyed again by fire in 1919. Built at the same time was the Grocers Warehouse 19.4 x 9.7m. This was a five-storey warehouse with one then two shipping holes. It was cut back into the Collyhurst sandstone river cliff face to the north of the Medlock. It was designed by James Brindley and incorporated a waterwheel driven hoist system. The canal arm was continued into a tunnel in the cliff. It was modified and extended in the first decade of the 19th century when the Rochdale canal was cut behind it. The tunnel was severed and became an arm of the Rochdale Canal. Part of the facade has been restored and the canal arms are bridged by two Dutch style lifting bridges.