Most of those aren't secret but are not widely known. Reminds me of the level -4 walk way at Heathrow Terminal 5. Avoid the crowds waiting for the train and tak

Most of those aren't secret but are not widely known. Reminds me of the level -4 walk way at Heathrow Terminal 5. Avoid the crowds waiting for the train and take a nice walk underground. You'll typically be all alone.