Aileach Castle, Near Elagh House, 33 Upper Galliagh Road, Londonderry, BT48 8LW

Aileach Castle is a ruinous stone turret situated on a prominent rocky outcrop near Elagh House, on the Upper Galliagh Road in Londonderry. Thought to date back to the 15th century, it is contemporary with Burt and Inch Castles. The castle was originally built by Neachtán O’Donnell, overlord of the O’Doherty clan of Inishowen, and later occupied by the O’Doherty family during the time of Docwra’s presence in the area. Following Docwra’s first expedition, Sir John O’Doherty began demolishing parts of the castle, but it was subsequently restored to Sir Cahir O’Doherty, son of Sir John, before falling into ruin after Sir Cahir’s death in 1608.

The remains of the turret stand approximately 4.5 metres high from the top of the rock. The outer stonework is a roughly random rubble of schist, creating an impression of concentric courses, although the stones are carefully chosen rather than shaped. These stones are generally around 150mm thick, with some smaller and larger pieces, extending for two or three courses. A continuous band of larger stones is visible approximately 900mm from the top. The inner core of the turret is composed of smaller stones. On one side, opposite the curved walling, there’s a greater degree of regularity in the stonework, possibly intended to stabilise the structure. A scraggly tree grows near the top, and the summit is covered in grass.

Historically, Burt Castle, upon which Aileach was based, featured a square keep with diagonally opposite, three-quarters engaged turrets – one containing a stairway, the other a latrine. A sketch of the turret is recorded in Colbay’s Ordnance Survey Memoir, likely based on an 18th-century drawing held in the manuscript library of Trinity College, Dublin. The site is accessible via a 30-metre laneway leading from the Upper Galliagh Road, and is currently owned by a local farmer. Aileach Castle’s setting is considered magnificent, offering a fine view of Grianan of Aileach, with the ruins of Inch Castle, constructed similarly, also visible. The monument record number is LDY No. 14A:3.