 The main location shoot for the episode was at Margam Country Park in Margam , Port <unk> in and around a converted <unk> which provided a location for the wedding and reception . Way states that one of the reasons Margam 's <unk> was chosen for the shoot was because of the " fantastic windows " which provided a good visual opportunity in regards to a sequence involving the alien Carrie jumping out of them . However , due to its listed building status the production crew were not able to remove the window glass for filming and had to construct replica windows on separate scaffolding using resin glass . The hotel exteriors and sequences set in the gardens of the wedding venue were filmed at <unk> Gardens in St Nicholas , Vale of Glamorgan . The hotel interiors were partly recorded at Court Colman Manor in the village of Pen @-@ y @-@ <unk> , <unk> and partly in studio . The opening sequence of the episode where Gwen pursues the shape @-@ <unk> was recorded on 19 November in a men 's public toilet in The Hayes , a shopping area in central Cardiff . 
