The calculated distance (air line) between Castletroy and An Muileann gCearr is approximately 77 miles respectively 125 kilometers.
By car or train, the actual journey to An Muileann gCearr is certainly longer, as only the direct route (as the crow flies) between Castletroy and An Muileann gCearr has been calculated here.
Air line (approximately)
125 kilometers
67 nautical miles