Serpukhov, on the southern approaches to Moscow, once possessed a white-stone kremlin commanding the crossings of the Oka basin, a key link in the defensive chain that shielded the capital from raids out of the steppe. Of that fortress, very little survives: a section of wall on the hill, the outline of the enceinte in the topography, and the churches that stood within and around it. The absence is itself the subject. Filmed in 4K, the programme uses the hill as a viewpoint over the town and its river landscape, reads the surviving masonry, and looks at the churches below the citadel, which preserve the character of the old town. A concise study of what remains when a fortress disappears and a place has to be understood from traces.
