The castle is situated in the small village of Portencross and is only a short drive from West Kilbride. The site has been fortified since the 11th century and the present tower castle is thought to date from the mid-14th century. Despite its age, the castle remains in remarkable condition and is a must-visit for anyone who loves history, architecture, and the great outdoors.

The castle was originally known as “Arneil” and was held by the de Ross family. After the victory at the Battle of Bannockburn in 1314, King Robert the Bruce gave the estate to Sir Robert Boyd of Kilmarnock. The castle was then rebuilt in the mid-14th century on a rock promontory at the bottom of Auld Hill and served as the caput of the Barony of Ardneil. It was from this location that King Robert II probably signed 15 charters between 1371 and 1390.

The castle was originally built as a stone-built hall house and had several alterations made to it by the Boyd family over the years. The castle has an oblong keep that is three stories high with a garret and a wing that is one story higher. The ground floor is vaulted and there are entrances on the ground floor and in the first storey.

Despite its age, the castle remained in use until it was unroofed by a great storm in 1739 and gradually became ruinous. However, the local fisherman continued to use the castle and may have made small alterations. The castle was eventually restored by the Friends of Portencross Castle in the 2010s and is now maintained as a museum.

Visitors to the castle will be able to see the magnificent architecture and learn about the castle’s rich history. The castle is also surrounded by stunning scenery, making it the perfect place for a picnic or a walk.