The London Board Game allows each player to initially close two stations each, and these stations can be changed during the course of play.
The rules I have don’t specifically preclude the possibility of closing one of the five main stations that players have to start and end at, but it makes sense this would be the case. However, the game’s Wikipedia page does explicitly state this as a rule:
Once the player has their cards, they can add two station blocks on any station - except the main red ones.
Does any version of the game’s rules make this abundantly clear?