On the largest of the islands in the Lake of Menteith (this is Scotland's only 'lake' as opposed to 'loch'!) stand the ruins of the priory of Inchmahome.
Mary, Queen of Scots, stayed here in 1547. Not that that is especially notable...where didn't she stay?
The priory was founded in the early 13th Century for a small community of the Augustinian order (the Black Canons) by the earl of Menteith, Walter Comyn. It would seem that his reason for founding the priory was so that the prayers of the canons would ensure the salvation of his soul.
The Chapter House (recently re-roofed) contains several effigies and gravestones, including a rather splendid effigy of Walter Stewart who died in 1295.