The film the Blair Witch Project can be a good choice for a open air cinema. Especially in the setting of an old country home. 10 years ago we drove all the way to Liverpool to show this film outside in a cemetery. The booking was for two nights. And on this venue we stayed in the cemetery overnight. Now that was eerie. Horror films outside can be a good choice. though it does exclude families with kids. Something to consider if you’re thinking of doing a horror film as a open air cinema.