Claire Brown's mind

Claire Brown's mind was the inner subconsiousness of psychic Claire Brown where a rogue Weeping Angel nested itself to protect itself from other Weeping Angels, specifically the Extraction Squad from Division that were attempting to capture it. The mind resembled a beach.

The Thirteenth Doctor entered the mind to confront the angel, offerring to protect it against the Extraction Squad in exchange for the Weeping Angel leaving Claire's mind. The Weeping Angel agreed, but eventually went back on the deal, offerring the Doctor to the Weeping Angels instead, who agreed to the trade, letting Claire's angel go while turning the Doctor into a Weeping Angel. (TV: Village of the Angels)

The rogue Weeping Angel was later forced from Claire's mind and imprisoned by Tecteun. (TV: Survivors of the Flux)