Hidden in a small car park behind Mungret Street, Fanning's Castle (also called Whitamore's Castle) is the surviving wing of a 16th-century tower house — three storeys of squared limestone with mullioned windows, a stair turret, and a small rear gable. It is one of the few standing pieces of pre-Williamite secular Limerick.
The building is a National Monument and is fenced for safety, but the exterior is fully visible from a few feet away. The contrast between the sturdy stone tower and the modern shopfronts around it is the point — half a minute as you walk between the Milk Market and the medieval quarter.