Can anyone help me with a question I have as to how we get to upper west, Astor on the Park. I understand to take the airtrain from JFK then change trains to go to Penn Station. Where do we go from there? I have looked at the map and cannot work out which line is which. The blue line (not sure which one that is) appears to go up to our hotel so do we need to change at Penn Station? Any help appreciated.