The calculated distance (air line) between An Muileann gCearr and Sandyford is approximately 49 miles respectively 79 kilometers.
By car or train, the actual journey to Sandyford is certainly longer, as only the direct route (as the crow flies) between An Muileann gCearr and Sandyford has been calculated here.
Air line (approximately)
79 kilometers
43 nautical miles