I found the location for the exterior aerial shots.

There is a business on the corner across the street from "Hotel Babylon" called Frost & Reed Ltd (it's a fine art gallery founded in 1808). Type that into google maps and there it is located on the corner of King St and St. James Square. Assuming up is north then the entrance to the hotel is southeast (from Frost and Reed). You can see the squarish vehicle entrance in the view. The hotel is located, also, a couple blocks north of St. James Park and directly across the street (west) from St. James Square Gardens. Hope this helps.