Cold, foggy start to fourth market. Officious in military boots, a policewoman from Cohen Brothers casting turns away any whose papers aren’t in order, or who argue about their pitch. Narrow medieval streets fill with tourists. Eventually I am placed next to a wiry old bird in the covered market. Every Sunday for 42 years she has set out her few vegetables on a folding metal picnic table. By midday she’s packed and heading home for lunch.