OK, So it's not really North Wales but it is a castle and, from the time of the Conquest, part of its role was to control the pesky Welsh, as well as the main routes from London to the North West. Only after Edward I made Chester his principal base in the north west did the importance of Beeston diminish.
The strategic importance of Beeston is instantly recognisable. It was a stronghold frompre-historical times, situated on a natural rocky outcrop, 100m above the CHeshire plans with unobstructed views across the Wirral to the north, Manchester to the east, North Wales to the west and a long way south.
http://www.english-heritage.org.uk/daysout/properties/beeston-castle-and-woodland-park/http://