Forest Fawr Country Park as Forest
The Doctor wipes the smushed spider off his foot outside the TARDIS and some Vikings arrive and take him and Clara hostage.
Source: The Doctor Who Locations Guide
“The Girl Who Died” Filming Locations
Clara and the Doctor end up in a viking village when the village’s warriors are taken by Odin.
Doctor Who episode “The Girl Who Died” was filmed in Cardiff & Newport in the United Kingdom.
Cosmeston Medieval Village as Viking Village
The vikings take Clara and the Doctor to their village which is soon attacked by the Mire.
Source: The Doctor Who Locations Guide
Uskmouth Power Station as Mire Ship
Clara and Ashildr talk to Odin on the alien ship.
Source: The Doctor Who Locations Guide