This medieval motte, first documented in 1976, consists of a steep-sided earthwork mound with a flat summit measuring roughly 17.6 metres north to south and 14.2 metres east to west. The mound, constructed from earth and stone, rises prominently from the undulating terrain, its imposing form still clearly visible despite centuries of weathering.

The fort’s construction reveals typical Norman defensive architecture, with faint traces of a fosse, or defensive ditch, still visible at the base of the motte. Small stones can be spotted protruding from the sides where erosion and damage have exposed the internal structure. Whilst the upper edges have suffered some deterioration over time, making it difficult to determine the exact original shape of the summit, the essential character of this defensive earthwork remains intact. A modern field boundary now curves around the base from the northeast through south and west to the west-northwest, incorporating this ancient structure into the contemporary agricultural landscape.

Unlike many similar fortifications of its type, Killalea Fort shows no evidence of an associated bailey; the defended courtyard typically found adjacent to such mottes. This absence suggests either a different defensive strategy or perhaps that any bailey structures were of timber construction and have long since vanished. The site stands as a solitary sentinel, a reminder of medieval power struggles and the strategic importance of controlling the Westmeath countryside during turbulent times in Irish history.