Manorbier is a rectangular enclosure Castle, curtain walls, and round and square towers. Its tower gateway was protected by a great door and portcullis as well as roof embrasures. There was no moat as the Castle stands on a natural promontory facing the coast. A postern gate provided access to the beach and boats.
There was an outer ward that was defended by earthworks but no barbican. The main gateway to the inner ward is across a bridge and dry moat. The south-east tower is round but the north-east one is angular. The domestic range of the Castle had kitchens, apartments and a Great hall that was built in the 1140s. Arrowslits were replaced by windows in the domestic range.
The Chapel, which was built around 1260, has elaborate vaulting and plaster-work. Some of the original medieval frescoes can still be seen.
