Marajó

Marajó (maɾaˈʒɔ) is a large coastal island in the state of Pará, Brazil. It is the main and largest of the islands in the Marajó Archipelago. Marajó Island is separated from the mainland by Marajó Bay, Pará River, smaller rivers (especially Macacos and Tajapuru), Companhia River, Jacaré Grande River, Vieira Grande Bay and the Atlantic Ocean. From approximately 400 BC to 1600 AD, Marajó was the site of an advanced Pre-Columbian society called the Marajoara culture, which may have numbered more than 100,000 people at its peak. Today, the island is known for its large water buffalo population, as well as the pororoca tidal bore periodically exhibited by high tides overcoming the usual complex hydrodynamic interactions in the surrounding rivers. It is the second-largest island in South America, and the 35th largest island in the world. With a land area of Marajó is comparable in size to Switzerland. Its maximum span is long and in perpendicular width. Marajó Island is separated from the mainland by Marajó Bay, the Pará River, some smaller rivers (especially Macacos and Tajapuru), the Companhia River, the Jacaré Grande River, Vieira Grande Bay, and the Atlantic Ocean. The island sits almost directly on the Equator. Together with smaller neighboring islands that are separated from Marajó by rivers, they form the Marajó Archipelago, with an aggregate area of . The archipelago is contained in the Marajó Archipelago Environmental Protection Area, a sustainable-use conservation unit established in 1989 to protect the environment of the region. Large parts of the islands are flooded during the rainy season because of higher water levels of the rivers along the coast and heavy rainfall in the interior. Marajó is almost entirely flat. During the rainy season, much of the island becomes flooded as a large lake. There are 20 large rivers on the island. Because of the changing water levels and regular seasonal flooding, many settlements are built on stilts (Palafitas). The island is known for the pororoca, a tidal bore phenomenon in the river that creates large waves reaching in height.