Imagine an entire jungle, summarized in a park. That’s the essence of the city’s incredible botanical garden, a 345-acre marvel (136 acres have been gardened and manicured to a fault) where visitors brush up against 10,000 plants of 1,500 separate species. Since 1908, it has served Rio as a sort of tropical guardian where the city’s greatest treasure—its nature—is gathered, studied, and even reproduced. It’s a must-do, rain or shine, and at certain seasons, sections like the orchidarium or the Queen Victoria water-lily pond really come into their own. Near the entrance, a stately alley of imperial palms has become the garden’s emblematic signature.