The calculated distance (air line) between An Muileann gCearr and Droichead Nua is approximately 33 miles respectively 52 kilometers.
By car or train, the actual journey to Droichead Nua is certainly longer, as only the direct route (as the crow flies) between An Muileann gCearr and Droichead Nua has been calculated here.
Air line (approximately)
52 kilometers
28 nautical miles