The calculated distance (air line) between Tuen Mun San Hui and Lam Tin is approximately 18 miles respectively 29 kilometers.
By car or train, the actual journey to Lam Tin is certainly longer, as only the direct route (as the crow flies) between Tuen Mun San Hui and Lam Tin has been calculated here.
Air line (approximately)
29 kilometers
15 nautical miles