The East Rail line is one of the ten lines that form MTR, the mass transit system in Hong Kong. The railway line starts at Lo Wu or Lok Ma Chau, both of which are boundary crossing points into Shenzhen and joins in the north at Sheung Shui and ends at Admiralty station on Hong Kong Island. At approximately 46 km (29 mi), the line is the second longest line within the network, behind the Tuen Ma line. The line's colour is light blue, formerly navy blue before the KCR/MTR merger.