The spectacular sets were built on the floor of a disused slate quarry near Bettys-y-Coed. It rained a great deal and shooting got behind.
Notes by Ian McKellen
Before Michael Mann had devised Miami Vice he directed The Keep and produced it and wrote it. He cast me as the heroine's father, a Romanian academic who gets caught up with Nazis and a monster trapped deep in the Keep. Ever-diligent, I had specially made my first trip to Bucharest and then had a couple of lessons from a dialect coach in London. So by the first day of filming I was ready to sound and feel authentically Romanian. Just before my first take as Dr. Cuza, Michael said: "Drop the accent - make him more Chicago." Well, if the writer/producer/director makes a request, you jump to it.
We filmed in North Wales, in the tiny village of Bettws-y-coed where tourists drop by for a five minute look at the pretty waterfall before driving off to clamber round Caernarvon or Conway castles. On my free days in Bettwys, it always seemed to be raining and the hotel was damp and drear.
The locations were spectacular whether outdoors in the disused quarry where the facade of the Keep was surrounded by an East-European-style village - or underground in the disbanded slate mines. Dr. Cuza had a strange disease that made him look 30 years older than he was. This was convincingly achieved after five hours in the make-up chair. For 12 days in succession, I was aged early each morning but never called to the set to work. I began a nervous breakdown or at least the line-producer thought so, because I was flown home from wet and dreary Bettys for a week-end's recuperation back home in London." — Ian McKellen, June 2000