| Piauí | |
| Official Name: | Portuguese: Estado do Piauí State of Piauí |
| Native Name Lang: | pt |
| Settlement Type: | State |
| Motto: | "Wounded and undaunted amid the ruins" |
| Anthem: | Hino do Piauí |
| Coordinates: | -8.2333°N -49°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Brazil |
| Seat Type: | Capital and largest city |
| Seat: | Teresina |
| Leader Title: | Governor |
| Leader Name: | Rafael Fonteles (PT) |
| Leader Title1: | Vice Governor |
| Leader Name1: | Themístocles Filho (MDB) |
| Leader Title2: | Senators |
| Leader Name2: | Ciro Nogueira (PP) Elmano Férrer (PP) Marcelo Castro (MDB) |
| Unit Pref: | Metric |
| Area Total Km2: | 251529.186 |
| Area Rank: | 11th |
| Population Footnotes: | [1] |
| Population Total: | 3271199 |
| Population As Of: | 2022 |
| Population Rank: | 18th |
| Population Density Km2: | auto |
| Population Density Rank: | 18th |
| Demographics Type1: | GDP |
| Demographics1 Footnotes: | [2] |
| Demographics1 Title1: | Total |
| Demographics1 Info1: | R$ 64.028 billion (US$ 11.877 billion) |
| Demographics Type2: | HDI |
| Demographics2 Title1: | Year |
| Demographics2 Info1: | 2021 |
| Demographics2 Title2: | Category |
| Demographics2 Info2: | 0.690[3] – medium (23rd) |
| Timezone1: | BRT |
| Utc Offset1: | -3 |
| Timezone1 Dst: | BRT |
| Utc Offset1 Dst: | -3 |
| Iso Code: | BR-PI |
| Postal Code Type: | Postal Code |
| Postal Code: | 64000/000 to 64990/000 |
Piauí (pronounced as /pt-BR/ pronounced as /pt-BR/) is one of the states of Brazil, located in the country's Northeast Region. The state has 1.6% of the Brazilian population and produces 0.7% of the Brazilian GDP.
Piauí has the shortest coastline of any coastal Brazilian state at 66 km (41 mi), and the capital, Teresina, is the only state capital in the northeast to be located inland. The reason for this is, unlike the rest of the area, Piauí was first colonised inland and slowly expanded towards the ocean, rather than the other way around. In the southeast of the state, the National Park of Serra da Capivara is a UNESCO World Heritage Site. The park has more than 400 archaeological sites and the largest concentration of rock paintings in the world, in a landscape dominated by canyons and caatinga.
The state has many notable archaeological sites, including Serra de Capivara National Park and Sete Cidades National Park, which are rich in remains of prehistoric Paleo-Indian and sedentary-based Indigenous Brazilian complex cultures.
Early settlers in the region included Francisco Dias d'Ávila from state of Bahia,[4] who brought the first herds of cattle to the area; and Domingos Afonso Mafrense, from Portugal, who founded what is today Oeiras.
In the 17th century, many impoverished noblemen and Jesuit priests, as well as black and Amerindian slaves, settled there. The first large-scale cattle farming also arrived with these settlers. Large estate owners seeking new pastures for their livestock arrived from neighbouring states such as Bahia and Maranhão.
At the beginning of the 20th century, the principal industry of the state was stock raising, which dates from the first settlement in 1674 by Domingos Afonso Mafrense, who established a number of cattle ranges. A secondary industry was the raising of goats, which were able to stand neglect and a scanty food supply. Agricultural products were cotton, sugar and tobacco. Forest products included rubber, carnauba wax and dyewoods. Exports included hides, skins, rubber, wax, tobacco and cotton.
Teresina was the first Brazilian city to be planned. In 1852, an architect designed it, after being inspired by a chessboard. Situated at the confluence of the Parnaíba and Poti Rivers, Teresina was (and still is) known as the Green City because of the countless mango trees that line the city's streets.
Piauí is bounded on the west by Maranhão, on the east by Ceará and Pernambuco, to the west by Tocantins, and to the south by Bahia. It has a short Atlantic coastline on the north.The Parnaíba River forms the boundary with Maranhão throughout its entire length; the state lies almost entirely within the basin of the Parnaíba and its tributaries. Part of the state on the Atlantic coast and along the lower Parnaíba is low, swampy, and historically malarial. South of this the country rises gradually to a plateau with open campos. This plateau region is watered by numerous tributaries of the Parnaíba, chief of which are, from south to north: the Poti, which has its source in the state of Ceará; the Longa; the Canindé and its tributary the Piauí, which is navigable for boats of one-meter draft up to Nova Iorque, a few miles above the mouth of the Gurguéia River. The river valleys are separated by flat-topped plateaus called chapadas, including the Serra Uruçui, which lies between the Uruçui-Preto and the Gurguéia, the Serra da Capivara National Park, which lies between the Gurguéia and the Piauí, and the Chapada das Mangabeiras, which forms the southwestern boundary of the state, separating the upper basin of the Parnaíba from that of the Tocantins.
The sandy soils along the Atlantic coast are home to the Northeastern Brazil restingas, low evergreen forests adapted to the nutrient-poor conditions. The lower basin of the Parnaíba is home to the Maranhão Babaçu forests, which extend westward into Maranhão. This ecoregion is dominated by stands of the Babaçu palm.
The eastern portion of the state is dominated by the dry Caatingas shrublands, which extend across much of northeastern Brazil. The Cerrado savannas extend across the southwestern portion of the state, in the basins of the upper Parnaíba and Gurguéia rivers. Enclaves of Atlantic dry forests lie in basin of the Gurguéia, forming a transition between the Cerrado and Caatinga. Serra da Capivara National Park is located in the Caatinga of the south-central part of the state, and protects numerous caves with ancient cave paintings.
The climate is hot and humid in the lowlands and along the lower Parnaíba, but in the uplands it is dry with high day-time temperatures and cool nights.
See also: Brazilians and Demographics of Brazil.