Once the home of Constance McEgan, this fine structure is situated on level ground in the farmyard of Sopwell Estate. Hall lies to the south east of the site. The land in the immediate area of the site is gently undulating pastureland. A tributary of the Ballyfinboy river flows due southeast to the south of the Scohaboy Bog lies further south. Lough Nahinch lies to the east. The top floor of the castle offers an excellent view of the surroundings countryside. Killaleigh Castle is a very large four-storey structure, with an unusual ground plan. The castle built in the early 17th century, has a tower at the southwest corner. This tower is 80 feet at the highest point, and measures 51 feet by 31 feet. It’s wall, windows and chimneys are in fair condition. The doorway is round headed of chiselled limestone, places on the east side.
The building contains 34 windows in all, some quadrangular, others round headed, all constructed of chiselled limestone with label mounting over them. One small round window, out of place with the other windows (a usual porthole window) is in the west wall. A Latin inscription over the window reads: “Ora Pro-Connor 1602”. It was donated by an O’Connor, in gratitude for having been saved in some fight or other. In the same wall there is a beautiful cross-shaped window, deeply chamfered and dressed. The masonry is composes of roughly cut-limestone, laid down in regular courses. The corners are finished with a series of cut and dressed quoin stones and a slight batter occurs at its base.
The most interesting feature in the interior is the stone newel staircase, 1.2m wide, which is equipped with a limestone banister, circular in section. The steps are of limestone blocks, which are now replaced by wooden steps on the upper floors. The first, second and third floors have been altered and their original features have been replaced with red brick. The murder hole for the castle occurs above the head of the doorway, internally. In describing the interior, it must be noted too that the floor levels have been altered. The positions of the windows indicate the original levels. The building was used in later years as a grain store and so steel girders were installed to support a large upper floor. The inner walls are lime-plastered and some of the wooden floors remain, though highly dangerous to walk on. The original roofline is visible on the east and west gables, and the wall walk remains intact. A high bawn wall encloses the castle site, and is interrupted at intervals by farm buildings. The ruins of a small rectangular tower occur inside the bawn wall at the southwest end. A number of corbels project out from the internal face of the wall – these originally supported a wooden wall-walk.