The calculated distance (air line) between Tuen Mun San Hui and Choi Wun is approximately 16 miles respectively 25 kilometers.
By car or train, the actual journey to Choi Wun is certainly longer, as only the direct route (as the crow flies) between Tuen Mun San Hui and Choi Wun has been calculated here.
Air line (approximately)
25 kilometers
14 nautical miles