Amazonia (sometimes called Pan-Amazonia) is a huge region covering about 40% of the South American continent. It encompasses most of northern Brazil, parts of northern Bolivia, eastern Peru, eastern Ecuador, southeastern Colombia, southern Venezuela, southern Guyana, southern Suriname and southern French Guiana. It is one of the world's most diverse biological areas and is fed by rivers taking their offspring in the Andes of Colombia, Ecuador, Peru and Bolivia and running into the Atlantic ocean in east Brazil.
You should always buy a snake bite kit, mosquito repellent. It is also important to stay hydrated and never go far from your tour guide.