Our bus breaks down on the middle of a mud-mired road on a high mountain pass, halfway between Shangri-la and Xiangcheng. A jolt, a stall, a splutter, then silence. The passengers, split between locals given to an air of resignation and tourists in poorly made, broad-brimmed ‘Ronaldinio’ hats exchanging timid glances, sit patiently until the driver has jimmied the ignition for a futile third time, then filter outside. With no town or further road for hours on either end, we sit and pace in anticipation as mountains unspool on every side, and the plunge into vast green valleys begins inches from our feet.

The Cai Rang Floating Market is just one of dozens that may be found across the length and breadth of the vast Mekong Delta in southern Vietnam, a trading network that helps buoy the most populous region in the country. Yet year by year, the number of boats dropping anchor before sunrise and displaying their wares on a tottering bamboo pole is shrinking. The market is found twenty minutes by motor boat east of the Mekong capital of Can Tho.