Secluding himself in a disused silk factory in rural france, Kiefer removes himself from the world, its ceaseless hubbub, in order to see it more clearly, question it more closely. Barjac is both laboratory and playground, a place where imagination is realized in concrete form.

Sophie Fiennes’ camerawork takes us into the labyrinth of his mind, beginning below the earth in a subterranean world of bunkers and tunnels, myths and secrets, before emerging into the silent lakes and forests that surround his many houses of memory and then finally moving skywards through his silent libraries and empty towers . One can hear the echo of Calvino’s ‘Invisible Cities’ when he says that ‘I can fill an empty room from my childhood’.

Everywhere in the film we witness the aftermath of action, the transformative effects of fire, earth and water on canvas, lead and concrete. The Sisyphean labour of construction leads, it seems, only to destruction. The flames that lick the blackened heaps of books in the closing frames are a burnt offering, to human dreams and their transience. Like Ozymandias, the towers will collapse in time and ‘over your cities grass will grow’. Kiefer’s art is an assertion of being in this world together with an acceptance of its passing, like the words whispered in chalk and charcoal that float over his walls and canvases.

The elemental scale of it all may recall the ambitions of American land art (Smithson’s jetty, Turrell’s crater), but its mysterious content is closer to Guadi’s buildings or Tapies’ paintings. For it is alchemy rather than science which draws him to the heart of things. The words of mystics, the numbers of Kabbalah, suggest other ways of exploring being and time. Stars are not explained by the restless classification of NASA scientists: ‘scientific progress has nothing to do with us’, he asserts. Echoing Heidegger’s approach to Aristotle’s metaphysics, what is unclassifiable is ‘after physics’. Time and existence are one, but ‘of the base of existence we know nothing’.

Through images rather than words, observation rather than explanation, Fiennes gives us not only a powerful document but a memorable experience, one that allows us to dwell awhile, even amidst the embers, with the child, the mystic, the maker and philosopher who is Anselm Kiefer.

Over Your Cities Grass Will Grow, a film of the work of Anselm Kiefer, directed by Sophie Fiennes. In cinemas from 15 October