With an area of roughly 49,600 square km (18,900 square miles), Ilha do Marajó is reputedly the world's largest river island. Its relatively unspoiled environment and abundant wildlife make it one of the few accessible places in the Amazon that feel isolated.
Ilha do Marajó's western half is dominated by dense forest and its eastern half by expansive plains, wetlands, and savannas. The island is ideal for raising cattle and water buffalo and has a half-million water buffalo and more than a million head of cattle; the human head count is about 250,000. According to local lore, the arrival of the water buffalo was an accident, the result of the wreck of a ship traveling from India to the Guianas.
On the island, you may see caiman, toco toucans, monkeys, and capybara, the world's largest rodent. Hiking is better in the dry season and boating in the rainy season. Warm, freshwater rivers are great for swimming, and there are numerous white-sand beaches to explore, making Marajó a good option for a few days of relaxation after a more intense jungle trek.
Local cuisine invariably involves the water buffalo, whether in the form of a succulent steak or in cheeses and desserts made with buffalo milk. There's also an array of local fish to try. Bring cash in small bills, as breaking large ones can be a challenge and credit cards are rarely accepted. In a pinch, beer vendors can usually make change.