In the first shot we see the heroes arriving in a car and a building can be seen up on the hill, I can't quite make out if this is Rawlinson House that we initially see but it certainly occupies a small hill in the park and this would mean the car is going in via what is now the entrance from Cotton Tree Drive. Of course, it could be this one was one of the other buildings in the park that has since gone, so I will keep my mind open at this point.
And in case you were still having doubts about where we are, we then get a glimpse of the front of the property. Feel free to compare it with this shot from the AMO. I do have shots of this area but unfortunately they were taken during a friend's wedding so they may not appreciate being splashed all over the internet, so I will go back and take some comparison shots if I get a chance this week.
For a bit of further confirmation, I think I may try and seek out the window space from the next shot, notice that the balustrades next to Frankie Avalon are of mixed design. The balustrades on the right hand side are the design that seem to feature throughout the building, but it looks as though at least 4 were replaced at some point. It would be nice to see if this little feature can still be discerned on the building. Watch this space.