The fragmentary ruins of Ardrossan Castle stand on a bluff that rises above the promontory on which the town of Ardrossan is built. The best access is from the north-west, from a set of steps that climb up between buildings on Glasgow Street.
This gives access to the open space on top of Castle Hill, also known locally as Cannon Hill. The highest point of the hill, slightly to the north of the castle ruins, gives superb views over the roofs of the town north along the coast towards Portencross, south over South Bay to Saltcoats, and west to the mountains of the Isle of Arran, fifteen miles away. To the north and east the views are of the hills that climb above the Ayrshire coast complete with a rather striking windfarm.
The surviving parts of Ardrossan Castle stand on the south side of Castle Hill, above slopes that descend steeply to the railway line below. Its location means that the castle is prominent in views across South Bay from Saltcoats, and from much of the southern end of Ardrossan itself, though its existence is far from obvious from the northern half of the town.
The castle carries signs warning not to approach it too closely, and though someone has at sometime consolidated the ruins, we'd share the recommendation to take great care when viewing them.
The ruins today comprise two main sections. The remains of the keep, built in the 1400s, form the most striking standing element. These rise in part to the third storey, though on the south side are completely open, revealing interior fixtures like fireplaces and some very weathered carved stonework. The continuation of the range including the keep contains a cellar whose entrance is blocked by railings. The second main element of the castle is part of the south range, apparently a vaulted structure in which a section of the cellar now forms a short vaulted tunnel.
A castle was first built on this site by Simon de Morville, probably in about 1140. By 1226 the laird was Richard Barclay de Ardrossan. During the Wars of Independence Ardrossan Castle was held by English forces for Edward I until captured by William Wallace. Wallace is said to have largely destroyed the castle and slaughtered the English garrison, dumping their bodies in a cellar, which later became known as "Wallace's Larder".
In 1357 the last of the direct Barclay line, Godfrey Barclay de Ardrossan, died without successors. The castle and estate subsequently passed by marriage to the Eglinton family. In the 1380s Sir John Montgomery, the 7th Baron of Eaglesham, married the heiress of Sir Hugh Eglinton and so became Baron of Eglinton and Ardrossan. Montgomery subsequently enlarged and remodelled Ardrossan Castle.
Much of the structure whose remains can be seen today dates back to a further remodelling and rebuilding of the castle which took place after Sir John's grandson was was made Lord Montgomery in 1449. The castle briefly became the main home of the Montgomery family after Eglinton Castle was attacked and burned down by the Cunninghams in 1528, but afterwards seems to have been allowed to decline. In 1654, troops from Cromwell's army of occupation removed much of the stone from Ardrossan Castle for reuse in the building of their citadel at Ayr, leaving only partial remains which have since served as a point of interest for visitors to Ardrossan.