The Peneda-Gerês National Park, also known simply as Gerês, is the only national park in Portugal (although many Natural Parks, Protected Landscapes and Reserves exist across the nation). It is located in the Norte region, in the northwest of Portugal.

The park was created on May 8, 1971 due to its national and international scientific interest, with the aim to protect the soil, water, flora, fauna, and landscape, while preserving its value to the existent human and natural resources. Education and tourism are also goals of the park.

The Peneda-Gerês National Park is located in the northwest of Portugal, extending through the municipalities of Melgaço, Arcos de Valdevez, Ponte da Barca, Terras de Bouro and Montalegre. The park has an area of 702.90 km². 52.75 km² of them are public property, 194.38 km² are private property, and the remaining 455.77 km² are commons.

There were a population of 9,099 according to the 1991 census, a 16% decrease from the 10,849 registered in 1981.

The park comprises a ridge of mountains, Peneda, Amarela, and Gerês. These form a barrier between the sea shore plains to its west and the plateaus to the east. The highest peaks are Nevosa (1,545 m) and Altar dos Cabrões (1,538 m) located at the border with Spain, so this mountains continue into Spain where they are known as Xurés.

An important feature of the landscape is the constant presence of water. Brooks and waterfalls are common at every mountain slope and the park is crossed by several rivers, namely: Cávado, Lima, Homem, Rabagão, Castro Laboreiro and Arado. There are dams across most of these: Alto Rabagão, Paradela, Caniçada, Vilarinho da Furnas, Lindoso.

The few tens of villages in the high lands are located near the arable lands. Terraces, built to make better use of these scarce lands, and traditional houses, with granite walls and thatch roofs, shape the landscape with an indelible, yet harmonious, human mark in some of the most isolated villages as Pitões das Júnias and Ermida.

The high lands have an average temperature of about 10 °C, ranging from 4 to 14 °C; and an average precipitation of more than 2,500 mm/year with more than 130 rainy days per year. Snowing is common in the Winter. The Homem and Cávado river valleys have a much milder climate, with temperatures of 8 to 20 °C, with an average of 14 °C; and an annual precipitation of 900 mm and around 100 days with rain.