This may seem obvious to everyone but me, but what I would like to know is - when you are looking at the Tube Map, I understand that the white circles mean that that is an interchange station. But what about a white circle that is connected to another white circle with a short line between the two? (I am thinking about what I see on King's Cross and St. Pancras, for instance). Does this mean that the two stations connect? Is it an underground connection? Is it a walking connection?

Sorry if this seems so simple, but I just want to be clear about it, and no surprises for my upcoming visit.

Many thanks in advance.

Londoners may pipe in here but, in my understanding, the answer is yes. It just shows that the stations happen to be one or two blocks apart and you can go through underground tunnel to reach them, which makes it easier to transfer between lines that serve each station. That's my memory anyways....I am envious of a trip right now to London!

Teaberry - King's Cross and St Pancras main line stations are very near to one another and share the same underground station. The little joining line that you see at quite a few stations on the underground map are simply a way of showing that a particular station is on more than one line (what you call an interchange station) and that is the only way they can show that in the drawing. It does not necessarily mean a long walk, (although it may do!) - it is just a feature of the design of the map.

I should also say that, conversely, at some stations e.g. Green Park where all the lines converge on one white dot, you actually have to walk quite a distance underground to get from one line to the other.

Thanks, both of you, for your help. That's what I thought, but just wanted to confirm.