Nash Point as Ko Sharmus
The Master forces the Doctor to travel with him to Gallifrey and Ryan, Ethan, and Ko Sharmus are left behind to fight the Cybermen.
“The Timeless Children” Filming Locations
The Master gives the Doctor a glimpse into the history of the Time Lords while her fam attempts to escape the Cybermen.
Doctor Who episode “The Timeless Children” was filmed in Cardiff in the United Kingdom and in South Africa.
Taff's Well Quarry as Gallifrey
The Master shows the Doctor the ruins of Gallifrey and gives her a glimpse of the past.
Taal Monument (Paarl Mountain) as The Boundary
Tecteun discovers a strange child at the Boundary to another universe.
Source: Who448 — Twitter
Oakdale Workmen's Institute as Guard Station
The Doctor sees the false images left in The Matrix of her past self working for The Division.
28 Craiglee Drive as New House
The other TARDIS lands on Earth getting Yaz, Graham, and Ryan along with the last humans in the universe back to safety.
Taff's Well Quarry as Ridge above Last Human Colony
The Doctor leaves the new TARDIS disguised as a tree and returns to her TARDIS.