The calculated distance (air line) between Yuen Long Kau Hui and Danshui is approximately 37 miles respectively 59 kilometers.
By car or train, the actual journey to Danshui is certainly longer, as only the direct route (as the crow flies) between Yuen Long Kau Hui and Danshui has been calculated here.
Air line (approximately)
59 kilometers
32 nautical miles