Rio is a city of water. It’s flanked by the South Atlantic Ocean on one side. That water is mostly blue. There is a bay called Gaunabara in the heart of the city. That water is dark in colour. A big lake sits just across the bay. It’s almost green. There are white waterfalls in the Tijuca forest in the middle of the city. Tiny rivulets, which look muddy at times, run through the city. And there are canals too whose water can appear from green to dark brown depending on the season.