The site consists of a rectangular platform measuring roughly 60 metres north to south and 44 metres east to west, enclosed by a substantial earthen bank. This inner bank, approximately 2.8 metres wide, rises about 30 centimetres on the interior side and 50 centimetres on the exterior. Running from the northwest to southwest corners, it defines the main living area that would have contained timber buildings during its occupation.

Beyond this inner defence lies a fosse, or water-filled ditch, spanning nearly 7 metres in width. This acted as the primary defensive feature, making the site difficult to approach whilst providing drainage for the enclosed area. An outer bank, slightly wider at 3.2 metres, completes the fortification system; it stands 70 centimetres high on its inner face and 40 centimetres on the outer. The western side presents a unique arrangement where a natural stream replaces the constructed defences, likely incorporated into the original design as both a water source and natural barrier.

These moated sites, common throughout the Irish midlands, typically date from the 13th to 14th centuries and were built by Anglo-Norman settlers or wealthy Gaelic families. The Raheenduff example, recorded in the Archaeological Inventory of County Laois in 1995, represents a well-preserved instance of this settlement type, with its banks and ditches still clearly visible in the landscape despite centuries of weathering and agricultural activity.