For some of the exterior location shoots in Italy footage of New York City, skyscrapers were superimposed in the background to make it appear like the film's New York City setting.
The scene at Central Park takes place during a lunar eclipse. However, the eclipse mimics the aesthetic characteristics of a solar eclipse with the Moon being completely blacked out, surrounded by a corona, just as if something had moved between Earth and Moon. However a real lunar eclipse doesn't appear to be pitch black but as a dark reddish layer and there certainly isn't a corona which is a feature of the sun.
When Marks finds a hole in the floor, when the cat jumps in the hole, a human hand can be seen grabbing the cat under the floor when it lands in the hole.
Towards the beginning, when the character played by Irene Miracle is swimming through the lost cellar room, she clearly is not wearing a bra; however, a few minutes later, after surfacing and returning to the building lobby, you can see that a bra has magically appeared under her dress.
What are the differences between the old British BBFC 18 Version and the Uncensored Version?
A
Due to Britain's Animals Act the old VHS by Fox had to be censored in two scenes. All cuts were waived for the rereleases by Arrow Video. A detailed comparison between both versions with pictures can be found here.