A floating island is a mass of floating aquatic plants, mud, and peat ranging in thickness from several centimeters to a few meters. Floating islands are a common natural phenomenon that are found in many parts of the world. They exist less commonly as an artificial phenomenon. Floating islands are generally found on marshlands, lakes, and similar wetland locations, and can be many hectares in size. Natural occurrences Sometimes referred to as tussocks, floatons, or suds, natural floating islands are composed of vegetation growing on a buoyant mat of plant roots or other organic detritus. In aquatic regions of Northwestern Europe several hundred hectares or thousand acres of floating meadows (German Schwingrasen, Dutch trilveen) have been preserved, which are partly used as agricultural land, partly as nature reserves. They typically occur when growths of cattails, bulrush, sedge, and reeds extend outward from the shoreline of a wetland area. As the water gets deeper the roots no longer reach the bottom, so they use the oxygen in their root mass for buoyancy, and the surrounding vegetation for support to retain their top-side-up orientation. The area beneath these floating mats is exceptionally rich in aquatic lifeforms. Eventually, storm events tear whole sections free from the shore, and the islands thus formed migrate around a lake with changing winds, eventually either reattaching to a new area of the shore or breaking up in heavy weather. Some cenotes in northern Mexico have natural floating islands. In the Brazilian Amazon, floating islands form in lakes on the floodplains of white-water rivers and are known as Matupá and range in size from a few square meters to a few hectares. In Crow Wing County, Minnesota a floating bog over in size moved about the area resulting in docks and boat lifts being destroyed. As decaying mass decomposes it releases gases which keep the bog floating. Pumice rafts Another type of natural floating island is the pumice raft, which is created by an explosive volcanic eruption, and can float on the ocean for months or even years before becoming fully saturated and sinking. They may assist in the migration of plants and animals. Artificial islands Floating artificial islands are generally made of bundled reeds, and the best known examples are those of the Uros people of Lake Titicaca, Peru, who build their villages upon what are in effect huge rafts of bundled totora reeds. The Uros originally