General Roy's map of 1750 shows a very extensive area of parkland at Eglinton laid out in an elaborate, radiating formal plan. By the 1st edition OS map in 1850 the only remnants of the early formal design were the rides in the south- west area of the estate, through Meadow Plantation and Crow Wood. This layout, possibly dating from 1801, when the Castle was rebuilt, is the basis for the designed landscape today although some elements have been lost.
The Eglinton family lived at Eglinton for many generations. Earliest records are of Elgin, Lord Elintoun, who lived in the reign of Malcolm of Scotland (1057-1099). In 1205 the name of Rudolphus of Elintoun appears. In 1361, Elizabeth, the daughter of Sir Hew de Eglintoun married Sir John Montgomerie of Eagleshame, a Norman family and they and their successors lived in Eglinton. In 1388 Sir John Montgomerie earned fame and fortune, and the niece of Robert II for his bride, by capturing Henry Percy at the battle of Otterburn; his ransom paid for the castle of Polnoon at Eaglesham. Sir John's grandson, Sir Alexander, (1429-1470) was raised by James II to the title of Lord Montgomerie for his work in the King's service, and his great- grandson Hugh was awarded an Earldom in 1508. He took the title of the Earl of Eglinton also becoming the Baillie of Cunningham, much to the fury of the Earl of Glencairn's Cunningham family with whom a long feud ensued; Eglinton Castle was burned down in 1526 and the 4th Earl, Hugh, was murdered in 1586.
A new castle was built and the estate was described in Thomas Pent's survey of 1608 as 'well planted and beautified with gardens, orchards and parks'. A famous beauty, Susannah, daughter of Sir Archibald Kennedy of Culzean married the 9th Earl, and the 10th Earl became famous for his agricultural improvements. The 11th Earl married Lilian Montgomerie of Skelmorlie, an heiress, and their son, Hugo, rebuilt Eglinton Castle on the site of the previous house. He also rebuilt the mansion at Coilsfield, and had the harbour at Ardrossan constructed.
The architect for the new castle was John Paterson, although plans were also submitted by John Baxter in 1775 (and his designs for the lodges accepted). John Paterson followed up his work with a court action against the Earl in 1823 for non- payment of his accounts between 1797-1806. Millar refers to the grounds being landscaped by Tweedie by 1801 but this has been neither substantiated nor refuted by the discovery of any plans. Loudon in 1824 comments 'the trees of the park are large, of picturesque form and much admired. The kitchen garden is one of the best in the country'. An article in 1833 in the Gardeners' Magazine makes similar remarks and comments on the 'many hundred feet of hot houses'; however, it also notes that the 'grounds are not kept up as they ought to be'.
The 13th Earl staged the celebrated Tournament in 1839, an imitation of medieval tournaments. It was staged on a jousting area four acres in extent, across the river from the Castle, and for this event the Tournament Bridge was built. Between 80,000 and 200,000 visitors arrived from all over Britain and the Continent, and one of the more famous participants was Prince Louis Napoleon Bonaparte. Two temporary saloons of 250' long were constructed for the banquet and the ball, and everyone wore costumes of the 14th & 15th century. Apparently it rained non-stop for the first two days of the Tournament and the event is reputed to have cost over #40,000 in 1839. The 13th Earl also took political office and in 1852 and 1858 he was appointed as Lord Lieutenant of Ireland. The 14th Earl was famous more for his horse racing and breeding.
By 1927 the family fortunes had altered so drastically that the family moved out of Eglinton and had the roof removed to avoid rate liability. A proposal for the conversion of the stables to a house in 1930 was never implemented. In 1940 the Castle was used by the army for gun practice and by the end of the World War II it was a ruin.
In 1953 Mr R. Clement Wilson approached Ayr County Council in his search for a suitable site in his native Ayrshire to open an extension of his Irish food manufacturing industry (Kennomeat and Kattomeat). He was hoping to find a historical site to convert into a factory for human food production, and the stables at Eglinton, though dilapidated, were sound and suitable for his purpose. The stable- block was converted into a factory and the grounds were opened to the public. In 1965 Mr Wilson established the Clement Wilson Foundation Ltd for the improvement of the environment. Part of the Castle was demolished and the rest was made safe. One of the 70' peripheral towers has been saved and this enables panoramic views over the surrounding countryside. In 1978 the park was gifted to Irvine Development Corporation as a public recreational resource.