Ellon Castle is a scheduled monument within the town of Ellon, Aberdeenshire. Only ruins survive of the 16th-century structure that may incorporate sections from the 15th century together with 18th-century renovations. The ruins form a focal point in a formal 6 acre garden planted in 1745; an older Category A listed sundial dating from c. 1700 forms the centrepiece to the garden.
The garden at Ellon Castle was conceived before 1745.
It could have been thought of that year or prior years, we do not know. The system must think that the idea had to be conceived previously, which is true, but it's not thinking months, just years.