The calculated distance (air line) between Jardine's Lookout and Yuen Long San Hui is approximately 15 miles respectively 25 kilometers.
By car or train, the actual journey to Yuen Long San Hui is certainly longer, as only the direct route (as the crow flies) between Jardine's Lookout and Yuen Long San Hui has been calculated here.
Air line (approximately)
25 kilometers
13 nautical miles