Llansannor Court as The Edison Manor (exterior & sitting room)
Donna and the Doctor attend a party hosted by Lady Edison and end up embroiled in a murder investigation.
Source: The Doctor Who Locations Guide
“The Unicorn and the Wasp” Filming Locations
Doctor Who episode “The Unicorn and the Wasp” was filmed in Newport & Cardiff in the United Kingdom.
Cefn Mably Lakes as Newlands Corner
Donna, Agatha Christie, and the Doctor fight the wasp and Agatha's car is left by the lake.
Source: The Doctor Who Locations Guide
Tredegar House as The Edison Manor
Donna, Agatha Christie, and the Doctor investigate the murder.
Source: The Doctor Who Locations Guide
St. Senwyr's Church as The Church
Reverend Golightly stumbles on some thieves in his church and transforms into the wasp.
Source: The Doctor Who Locations Guide
Penylan Road as Car Chase
Donna and the Doctor follow Agatha Christie who is being chased by the wasp.
Source: The Doctor Who Locations Guide
Hensol Castle as Swan Hydropathic Hotel
The Doctor drops Agatha Christie off at the hotel after an adventure in the TARDIS.
Source: The Doctor Who Locations Guide