It is the only motte and bailey castle on Anglesey, and was apparently used by the Home Guard in WW II.
History
The first iteration of Castell Aberlleiniog was a traditional mottte and bailey fortification, with a high earthen mound surrounded by an enclosure, or bailey. The builder was likely Robert of Rhuddlan, the Commander of Troops for the Earl of Chester.
The castle was attacked and burned around 1094 by the Welsh prince Gruffydd ap Cynan. This attack is known as The Battle of Aberlleiniog.
The castle was owned by nearby Penmon Priory from the 13th-century until the priory was suppressed by Henry VIII in 1537. It was refortified during the English Civil War and used by Parliamentarian troops during the siege of Beaumaris Castle in 1648. It was subsequently attacked by Royalists under Colonel John Robinson.
The stone ramparts you can see at the top of the castle mound are not the original medieval structure. They may have been added during the Civil War, or perhaps later, during the 18th century. During the following century, the castle was used as a picturesque garden folly, with the north tower becomming a summer house.
Lady Cheadle's Fort
At the time of the Civil War, Aberlleiniog Castle was owned by Thomas Cheadle, who served as the Deputy Constable of Beaumaris Castle and acted as a land agent for the powerful Bulkley family. He was also a pirate, and served three separate gaol terms.
Cheadle was strongly suspected of carrying on an affair with Lady Anne Bulkley, the wife of his employer, Sir Richard Bulkley IV. When Sir Richard suffered a sudden death, Cheadle and Lady Anne were tried for his murder. They were acquitted, and later married.
Getting There
Castell Aberlleiniog can be reached only by footpaths, with access from the north and south.
Perhaps the most interesting route is from the centre of Llangoed, to the north, where a series of information panels outlines the history and archaeology of the castle and the surrounding area.
From here, a trail follows the Afon Lleiniog to the base of the castle mound. This is a lovely, peaceful walk through the heart of the Aberlleiniog Local Nature Reserve, an area of beautiful woodland.
You climb the motte by way of wooden steps which zigzag their way up the slope.
The castle is set in a heavily wooded area, so it can be difficult to make out the shape of the motte and its surrounding bailey, but the later stone fortifications at the top are quite impressive.