Ok, see this sentence "*London is known for Big Ben*".

So, does the idiom "*to be known for*" mean "*to be well-known for*" or "*to be famous for*".

Like "*London is known (famous) for Big Ben*"?

I could not see any website say that "*to be known for*" = "*to be famous for*"

 What does the idiom "to be known for" mean?