The Game of Thrones cast were "smothered in blankets" when they travelled to set every day.
The fantasy drama series came to an end after eight seasons at the weekend and Isaac Hempstead Wright - who plays newly-crowned king Bran the Broken - has revealed the lengths producers went to in order to keep plot details under wraps during filming.
He said: "The phenomenon of 'Thrones' is not something I am ever likely to experience again in my life. The level of hysteria and speculation around it is unprecedented.
"When we shot those final scenes of the Starks on the bay in King's Landing, we were told not to leave our hotel room in Croatia for fear of giving something away.
"When we got into the cars to go to set, we were smothered in blankets to obscure our faces and costumes."