Markree castle.Markree castle is a castle located in Collooney, county Sligo, within the republic of Ireland. The castle is the ancestral seat of the Cooper family. Markree is also partially moated by the river Unshin. Today it functions as a small family run hotel. During the 1830s, the properties’ observatory boasted the largest refracting telescope in the world and during the 1940s the Coopers’ observatory staff sighted and discovered what is known today as the “Metis 9” asteroid. The original 14th century construction on the site was a military outpost of the Irish Mcdonagh clan, who served under the O’Briens. When the O’Briens were defeated by Oliver Cromwell and his troops, the estate was confiscated and granted to the Cooper family. The coopers saw more turbulent times during the military exploits of the catholic king James, which forced the Coopers to abandon the land. After King James and his catholic forces were defeated by William of Orange at the battle of the Boyne, the Coopers returned and have remained there ever since, despite a brief period where the property was occupied by the Irish free state army.