Castletroy is one of the fastest-growing residential areas in Ireland and has now engulfed the old villages of Annacotty and Monaleen (Móin a lín - field of flax).

The Castletroy Shopping Centre extends to some 90,000 square feet (8,400 m2) and is located off Dublin road at Kilmurry roundabout adjacent to the Briarfield estate.

The MacKeoghs continued to hold land in Castletroy, but at some point before the reign of Elizabeth I the castle was taken over by their overlord, the Earl of Desmond.

The Earl of Desmond rebelled against the English monarchy and their lands were foirfeit and the Castle Troy became the property of Sir John Bourke of Brittas.

According to tradition when Cromwell landed in 1649 with his New Model Army his general Henry Ireton in 1651 led an army on Limerick and set up cannons on Harty's Hill and battered the castle as it was ideally positioned to defend the city against forces moving down the River Shannon.

This dates from the late 19th century when Limerick had a sizable Jewish community and was renovated and reopened by Chief Rabbi Mervis in 1990.