Proposition

[Mirahmad]

Dear Sir/Modam

I would like to know about this sentences

Have you been to London?
Have you been in London?

Which one of them would be correct?

[Boadicea]

In my experience, only "Have you been TO London?" is correct, although we use the preposition IN in most cases where we use the verb TO BE:

I'm IN London (Present Simple)
I was IN London yesterday (Past Simple)

but: I've been TO London (Present Perfect)
I'd been TO London (Past Perfect)

I only use the the verb TO BE + TO in Perfect tenses