Castrovalva actually exists! It’s a village in Italy less than one hundred kilometres away from Picinisco, the town where Peter Capaldi’s grandfather was born). Castrovalva, the village, is in the Province of L’Aquila in the Abruzzo region of Italy and clings onto the top of a steep hill.
Is this the connection between the picturesque village and Davison’s first story? The fact that the city the Doctor, Tegan and Nyssa are heading for is also on top of a rocky cliff? But it isn’t as simple as that. Christopher H Bidmead, the author of the story, was keen to introduce real science into Doctor Who and move the series away from the fantasy of the stories devised by Douglas Adams and Graham Williams. True to type, Bidmead was interested in the mathematical principle of recursion, which his story “Castrovalva” centres on. Recursion is the process of repeating items in a self-similar way. When two mirrors are exactly parallel to each other, the images which occur are a form of infinite recursion. A computer science student might learn that procedures for calculating factorials or Fibonacci numbers are classic examples of recursive programming. There is also a geeky joke: “In order to understand recursion, one must first understand recursion!” In the story itself when the fictional city collapses in on itself, we have an example of spatial recursion. Nyssa describes recursion as ideas which “fold back on themselves”. Tegan tries to grasp the concept saying “if we had an index file, we could look it up in the index file under ‘index file'”. Maybe the Doctor himself can make things clearer, in this exchange from the story.
DOCTOR: How do I know you’re telling the truth?
MERGRAVE: Because, sir, I maintain I am, and I am a man of my word.
DOCTOR: A perfect example of recursion, Mergrave. And recursion is exactly what we’re up against.
But what or rather who is the connection between Bidmead’s hard science and the pretty little village of Castrovalva? Let me explain. It is an artist. M.C. Escher. Maurits Cornelis Escher (1898-1972) to be precise. He was a Dutch graphic artist, whose work featured impossible constructions and explorations of infinity. His 1930 lithograph print (shown below) is one of his most famous works. And its name? “Castrovalva” of course! He produced it after visiting the village in 1929. The design of Bidmead’s fictional city and the concepts and ideas in the story reflect the impossible nature of Escher’s work. Herein lies the connection.
Escher’s work shows his fascination with the high and low, the near and far. It has been described as an expression of the excitement of three dimensionality, not as an abstract concept, but in its full reality. The artist described his experiences in Castrovalva: “I spent nearly a whole day sitting drawing beside this narrow little mountain path. Up above me there was a school and I enjoyed listening to the clear voices of the children as they sang their songs.” Was Bidmead thinking of these children, when he wrote the little girl in the story telling the Doctor that three follows two?
But most intriguingly of all Escher himself “enjoyed” an adventure worthy of the Doctor, when in spring 1929 he spent his first night in Castrovalva. Escher had gone all alone to the village as he wished to sketch there undisturbed. He arrived late in the evening, found a place to stay and fell asleep. But suddenly at five in the morning he was woken by heavy knocking on his bedroom door. There was a shout: “Police!” He had no idea what these Italian “carabinieri” wanted from him, but his passport was confiscated and he was taken to the police station. His crime? Escher had apparently made an attempt on the life of the king of Italy. This impossible accusation was the result of an old crone’s gossip. She had noticed him, a foreigner no less, arriving late the previous night. In her account of events, Escher hadn’t taken part in a local “Castrovalva” procession that night and he had had an evil expression (“guardava male” were her words). She had simply reported this “evidence” to the police. It was a crazy story and Escher, incandescent with rage, did his best impression of the Ninth Doctor locked up in a cell with a Dalek. The artist threatened to kick up a fuss in Rome and it worked. He was set free.
Unlike the “impossible” Castrovalvan celery Davison’s Doctor would famously wear on his lapel and indeed the city itself, the village of Castrovalva in Italy is quite real. If fancy took us, we could quite easily hop on a plane and fly there. You certainly can’t say that of Skaro or Raxacoricofallapatorius!