During the walk she takes with Michelle de Kretser along the Cooks River, the bit that snakes between Hurlstone Park and Tempe, Belinda Castles, the author of Walking Sydney, muses on the impact of Sydney’s geography. ‘On the footpath-climb to skirt the golf course,’ she writes, ‘the village-like nature of Sydney makes itself felt, the way suburbs are enclosed and cut off by ridges and valleys, cliffs and rivers, the tentacles of the harbour. A city’s form has an effect on thinking and ways of being.’