Run, walk, hire a tandem or pedal a swan boat around Rodrigo de Freitas Lagoon, known to everyone as simply the lagoa, for one of the simplest but most pleasant evenings you can spend in Rio.
Stop along the 7.4km course way for fresh coconut juice, a cold chope (draught beer) or an evening meal at one of the lakeside restaurants (my favourite is Arab da Lagoa, which serves hummus and pitta).
While taking in the famous landmarks (Christ the Redeemer, the Dois Irmãos and Pedra da Gávea mountains) and the Rio cliches of footballers, skateboarders and keep-fit fanatics, keep your eye out for wildlife, especially herons and capybara – the world’s biggest rodent. The water’s notoriety for stinking pollution and dead fish is not undeserved, but is usually only noticeable one month a year.
As far as possible, however, avoid driving anywhere near the Lagoa. The traffic is a nightmare.