Hay Tump is a late 11th or early 12th century earthwork motte and bailey fortress and was probably founded by William Revel, a knight of Bernard de Neufmarché. Standing in the independent commote of Melinog, immediately across the Login Brooke from St Marys church, the castle may be the predecessor to or occupied simultaneously with Hay Castle. The circular, flat-topped motte is well-preserved but its summit was disturbed for World War II civil defence and the site of the bailey is the levelled north-eastern platform, which is now partly a car park.