Hillsborough Castle
County Armagh, Northern Ireland
Hillsborough Castle is a castle in County Armagh, Northern Ireland, first built in 1799. It is a Grade B+ listed building. The nearest other castle is Ballyroney Castle, 12 mi away. It is owned by monarchy of the United Kingdom.

Hillsborough Castle at a glance
Built
1799
18th century
Type
Castle
Cared for by
monarchy of the United Kingdom
Heritage status
Grade B+ listed building
About Hillsborough Castle
Hillsborough Castle is an official government residence in Northern Ireland. It is the official residence of the Secretary of State for Northern Ireland, and the official residence in Northern Ireland of the British monarch and other members of the British royal family when they visit the region, as well as a guest house for prominent international visitors.
From the Wikipedia article on Hillsborough Castle, CC BY-SA 4.0.
Hillsborough Castle sits at 54.4612, -6.0861 in County Armagh. The closest other castles are Ballyroney Castle (12 mi), Belfast Castle (14 mi) and Tandragee Castle (15 mi). County Armagh has 16 castles in all.