The largest stretch of urban jungle in the world, Tijuca National Park is home to Corcovado mountain and the Christ statue as well as being the setting for some serious outdoor pursuits. It isn't advisable to enter the jungle without a knowledgeable guide - not least because getting lost would be all too easy - but visitors can take their pick pick from a vast range of guides and tour operators running everything from hop-on, hop-off sightseeing drives to mountain-climbing adventures. Natural pools and waterfalls provide an opportunity to cool down, but be sure to bring plenty of drinking water.