Castletroy (Irish: Caladh an Treoigh) is a suburb of Limerick, Ireland and is the largest suburb in Munster. Its population is estimated at 40,000 as of 2010.Historically, the district was entirely separate to Limerick, and consisted of little development aside from the villages of Annacotty and Monaleen. With the creation of the University of Limerick, as well as the growth of Limerick city itself, this began to change.