Shipping Route : Quebec to Liverpool and Castles

Hello I am doing some research on a travel diary of one of my relatives dating back to 1874 who sailed from Quebec to Liverpool on the S.S. Samaritain (Allen Line) Does anyone have information on the most likely route taken by the S.S. Samaritain in late 1874 from Quebec to Liverpool. I am trying to identify a landmark referred to as the ruins of a “Green Castle” that was observed during the trip to Liverpool. According to the diary, this castle was bombed by Cromwell. It may be Dunnotar Castle in Scotland, but I doubt if the Samaritain sailed along the east coast of Scotland. Otherwise it could be Caernarfon Castle or Beaumaris in North Wales. Then again could it be the ruins near Antrim. Could any of these castles observed from aboard the ship. Your help is appreciated. Best regards, Gorgumplatz