Which of these sentences is correct?
1- We often go to visit our friends in Cambridge, which is not far from London.
2- We often go to visit our friends in Cambridge, where is not far from London.
I've learnt in grammar books that when you are talking about places in relative clauses, you should use "where" to give some information about that place, I know in the above question the first sentence is correct, but why? Cambridge is a place, isn't it?