According to the Annals of Innisfallen, this impressive earthwork was constructed in 1193 AD when foreign forces built a castle here with the permission of Ua Briain, apparently to the detriment of the local Desmummu people. The motte rises dramatically from its surroundings; approximately 10 metres from its distinctive berm and a full 20 metres from ground level, with a flat top measuring roughly 21 by 22 metres across.

What makes Bruis Moat particularly fascinating is its layered history and unusual construction. The builders cleverly adapted a natural hillock, scarping around it halfway up before piling the excavated material on top to create the current imposing form. This technique resulted in the wide, flat berm that still encircles much of the structure, though quarrying from the south through west to northwest has altered its original profile. Intriguingly, skeletal remains discovered in the exposed southern face hint that this site may have served as a prehistoric burial mound long before the Normans arrived, adding another chapter to its complex past.

Today, visitors will find the tree covered motte crowned with an unexpected addition: a small two storey summer house dating from the 18th century. Built from uncoursed sandstone rubble, this compact structure measures approximately 4.2 by 4.8 metres internally and features fireplaces on both floors, suggesting it served as a comfortable retreat for local gentry. Located just 160 metres north of a medieval church and graveyard, Bruis Moat stands as a solitary sentinel; unlike many Norman mottes, no evidence of a bailey has been found around its base, making it an unusual example of medieval military architecture in Ireland.