Eglinton Castle is situated a mile (1.5 km) southeast of Kilwinning next to the River Lugton in North Ayrshire. It was built in 1796 by John Paterson for Hugh Montgomerie (1739 - 1819), the 12th Earl of Eglinton, a member of the Seton family. The new building replaced a 17th-century castle which had occupied the site.
A bitter dispute between Paterson and the Earl resulted in Paterson taking legal action for the recovery of fees and expenses. The action was raised some 13 years after the Castle was completed, and not settled until 1829, some ten years after the Earl's death. Paterson was awarded a level of compensation, but it was recognised there had been shortcomings in his supervision of the work and charges which he had made.
The castle, unoccupied and forlorn by 1925, was further damaged when it was used for commando training during World War II. It was largely demolished in 1973, only a corner tower and foundations remain.