By These Ten Bones by Clare B. Dunkle. New York: Henry Holt, 2005.
Many castles in the Highlands were built right next to a large body of water, both for protection and for ease of transportation.
Here is another castle built by the water. Although you cannot see the loch, which lies out of sight behind it, you can see the boggy ground in front of it, which visitors are crossing on a bridge.
It is hard nowadays to find a castle exactly like Lady Mary's. Although they were a common type throughout the Highlands, and although many of them still exist, they have been modified from their original uncomfortable form by later inhabitants. This is Castle Menzies, built around the time Lady Mary's castle was built and used for four centuries thereafter. The tower at the side houses the staircase, just as Lady Mary's tower does, and was originally the only entrance, as hers is; the central door that you see here was added much later. The windows were also enlarged much later, as the castle made its transition from being a stronghold of defense to a wealthy family's mansion.
Here is a view of the attic of Castle Menzies, the area most like its medieval form. You can see here that almost the entire interior is one huge room, just as in Lady Mary's castle, and it looks drafty and dim. While the windows on the one side are larger than they were in the Middle Ages, the windows on the other side have been bricked in; originally, there would have been some light from both sides. Only the wealthiest families in the Middle Ages had the benefit of glass panes, so Lady Mary's windows are open to the outside air.
This room shows the sort of furniture that Lady Mary might own. The curtains around the bed helped to keep its owner warm at night in a chilly, drafty castle, and the tapestries on the wall might be similar to the ones Lady Mary has brought with her, or even the ones she herself works if she is particularly skilled.