Mountlong Castle lies on the eastern bank of the River Stick, in the Mountlong townland, south of the town of Belgooly, in County Cork in Ireland.
Mountlong Castle is a semi-fortified stronghouse built in 1631 by John Long. It was only occupied for about a dozen years before being burnt during the conflicts of the 1640s.
It consists of a rectangular main block with four, boldly projecting, square corner towers. The western towers are very ruined but the east towers still stand.
Mountlong Castle bears a big resemblance to Monkstown Castle suggesting that the two properties may have been designed and constructed by the same builder, although Mountlong doesn't have bartizans like those at Monkstown.
A beautiful ruin. As it is located on private property, next to a farm, it can not be visited.