It is a little confusing to get to the Chapel, so here are directions as best as I can describe. First, Get to Top of the Rock by either shuttle or driving (don't forget if you drive you must use the valet). When you arrive at Top of the Rock, enter the building. Then, take a right at the Woolly Mammoth and go through the doors to outside. Proceed down the walkway until it opens for outdoor restaurant seating. There will be an elevator on your left. Take it down to the first floor. Then go through the building, past the bar, then outside again. Turn left when you get outside and you will see the Chapel.
The Ceremony begins at 5pm but I would arrive no later than 4. That will give you time to enter, park, ride the shuttle and then walk to the Chapel. October is their busiest time of year so there may be a lot of traffic, people waiting for shuttles and you may have to park a ways from the welcome center. Shuttle lines can be long, so be sure to give yourselves enough time so you aren't rushed.
Dinner will be served around 7, followed by cake. There will be a cocktail hour after the ceremony, around 5:30.
We have the room until 1 am so please feel free to stay as long as you like. There will be a DJ so we can dance the night away!