In season 19, episode 1 of Dr Who the Fifth Doctor visits the settlement Castrovalva, not knowing that the Master has laid a trap by tweaking around with the layout of the place. The episode was obviously inspired by the works of M.C.Escher with obvious references like the name and outwards look of the castle, similar to the lithograph of the same name.
While the inside seems to be inspired by the painting Belvedere
The physics of the place also takes on more Escher-like qualities over the episode.
One thing that is odd, however, is a group of washerwomen that always seems to reside in the square at the centre of the castle.
Their manner of dressing, and the fact that they have a whole side story dedicated to them, where an important cabinet gets stolen from the Doctor to be used by them as a washbasin, makes me think they also was inspired by a painting, probably by Esher. I have no idea which one that would be though.
Anyone that has any insight into this ?