Station 1 is the first station of the Canals map in TnB. It is located on a red big train-car, with a small hatch and a ladder. In Half Life 2, there is a refugee and a Vortigaunt in this station. You can also see GMan here, just quickly look at the TV when entering the dumpster, he is right there.
Station 1 is located near the spawn on the map used by the TnB Server 2. Since the recent Mingebag increase on the servers, this has been the first security station. You must reveal your identity and destination to a guard, who then will broadcast where are you going, your name and await confirmation.
In City Eight, the canals is somewhat different. For one, it acts as the outlands, instead of the canals, at this point. It has a roster, and you may only travel back and forth by City Eight Resistance Or Lambda Movement Personnel. In addition, it is not as linear. Station One in the City Eight canals is slightly more challenging to get to. Once you've entered the underground section, you go to the point where you can see the sewage-way, with the large grate, and enter the doorway on the right, and the room you enter is Station One. It is used as a common room, and occasionally people will use it as a meeting place, or as a place to sleep.