A summer evening in San Fernando, the heat finally easing, and around a thousand runners line up outside the Estadio Iberoamericano in Bahia Sur for an 8pm start. From there the field pours out through the town and threads its way along the main avenues, past La Carraca and the Avenida de la Armada, before the finish on Calle Arenal in the centre. The leaders usually come home within about half an hour, the rest trickling in behind them.
You don't need to run to get something out of it. Locals gather along the route to cheer, and the closed streets give the whole place a relaxed, communal feel for an hour or so. Worth knowing if you're staying nearby: roads and parking shift from late afternoon, so leave the car well clear and walk in.