Trains to Hong Kong's New Territories and Lantau Island 

Hong Kong's rail network is operated by the MTR (Mass Transit Railway) Corporation. It includes a system akin to the London Underground or a subway - with mostly underground lines; as well as a railway line to Tung Chung and the airport, north Lantau, and the north-south running East Rail and West Rail. The latter two were originally operated by the Kowloon Canton Railway (KCR), but this was merged with the MTR Corporation in December 2007.

The "subway", long known as the MTR (perhaps will remain so?) is wonderful for getting around in the city, with lines serving much of north Hong Kong Island, as well as Kowloon and, via the Airport Express line, north Lantau.

There's an interchange with East Rail at Kowloon Tong; and two interchanges with West Rail - at Nam Cheong on the Tung Chung-Central line, and at Mei Foo. The Diamond Hill and Choi Hung stations are close to stops for buses heading to Sai Kung and Clearwater Bay; Shau Kei Wan station is by the bus station serving Shek O.

Cross-border trains run on East Rail, but most trains are local, running between East Tsim Sha Tsui in Kowloon (the station here has underground walkway to "MTR" line - takes maybe 5 minutes or more, so if I'm northbound from Central I still keep to MTR to Kowloon Tong, then change), and stations to Lo Wu/Lok Ma Chau on the border.

Tai Po Market is among key stations for accessing rural Hong Kong: from here there are buses east to Tai Mei Tuk and Bride's Pool, and west/orthwest through the Lam Tsuen Valley with stops at or near Kadoorie Farm and Ng Tung Chai; and you can take a taxi to Tai Po Kau Forest Reserve. University station is a roughly ten-minute walk from the Ma Liu Shui ferry pier, from which there are ferries east through the Tolo Channel.

Especially if you ride a train to/from the border at Lo Wu, East Rail can be pretty crowded, so you may want to consider riding First Class. If you do so and you're using an Octopus card, remember to wave it over the upgrade terminus-thing, on a wall or pillar by the entrance for the First-Class compartment. (Yellow signs point the way to the spot on the platform where the First-Class coach will halt.)

West Rail offers a fast, smooth ride, but unless you are interested in birding - in which case, the Kam Sheung Road station is within a relatively short taxi ride of Mai Po and close to Kam Tin, Tin Shui Wai is close to Tsim Bei Tsui (a taxi ride) and a Light Rail trip from the new Wetland Park - it isn't so great for getting to wild Hong Kong. This is because, sadly, the line mainly serves northwest Hong Kong - much of which has been trashed by container parks, scrapyards, and development that generally seems to have occurred with little or no sense of aesthetics. But you may have your carriage almost to yourself. (Even people commuting from the northwest aren't flocking to West Rail.)

There's also the Light Rail system, connecting urban areas in northwest Hong Kong; there's a station by the Hong Kong Wetland Park, Tin Shui Wai.