I walk all over Manhattan. I walk fast and I can walk from Penn Station to 28 Gramercy Park in 30 minutes. If you walk at a medium clip, you can do it in 40-45 minutes. If you dally, it'll take you an hour. If you're carrying a heavy bag, don't walk it at all -- take a cab. Cabs wait in a line in front of Penn Station -- right on 7th Avenue. It's not that long of a walk (at least for me). Getting out of Penn Station can be tricky -- there's so many exits, and it's like Times Square during New Year's Eve down there at rush hour. You want to get out on the 7th Avenue (Seventh Avenue) side. So just ask someone to point you that way. If you do end up getting out elsewhere, just ask anyone to point you to 7th Avenue. Now, I would say the easiest way to walk there is to walk south (that's downtown -- the street numbers decrease as you go south -- and, as you leave Penn Station, that's to your right).... so walk south on 7th Avenue and go to 23rd Street, which is only 10 blocks. Make a left (now you'll be walking east) on 23rd Street (23rd Street is a major crosstown street, where traffic goes both ways... you're always safer on a major street like that), and walk to Park Avenue South. You will pass the following avenues (as you're walking east on 23rd street: you will pass 6th Avenue (which is also known as "Avenue of the Americas" -- that's what the street sign will say, but New Yorkers know it as 6th Avenue), then 5th Avenue and Broadway (5th Avenue and Broadway meet (and cross each other) at 23rd Street), and then you'll reach Park Avenue South. At Park Avenue South, turn right (now you'll be going south again) and go 3 blocks to 20th street. At 20th street, turn left (now you're going east again), go one block to Irving Place (before you get to Irving Place, Gramercy Park begins [it's an actual little park] -- once you pass Irving Place, look at the buildings on your right and look for #28. I just looked at "Street View" on google.maps, and I think the Shul is just past the park itself (it's a small park), on the right side. Good luck. And, again, if you're pressed for time, just take a cab. It's gotta be under $10 to get there. And good luck.