The Lim valley (Limska draga or Limska dolina) is the 35 km long valley of the river Pazinčica, which transforms into the Lim Channel (Limski kanal), a 10 kilometers long estuary. Estuaries and coastal waters are among the most productive ecosystems on Earth, providing ecological, economic, cultural, and aesthetic benefits... The estuary is sometimes called a fjord. Although the movie The Vikings starring Kirk Douglas was shot there in 1958, it isn't a fjord but a ria, since it wasn't carved by a glacier but by the river eroding the ground on its way to the Adriatic Sea.The area around the channel has been inhabited since the Neolithic era. These early settlers burrowed into caves along the valley which have been excavated to reveal remnants of their former occupants. Ancient Illyrians then moved in and settled around the hill-fort of Gradina. Under the Romans, the channel formed the border between the administrative units of Porec and Pula. The name lim is derived from the Latin limes for border. According to legend, St Romuald, founder of a nearby monastery inhabited one of the ancient caves for several years in the 11th century. The 105m long St Romuald's cave is open for visits in the summer.Fishing in the Lim Channel has always been excellent. Now the natural species have been augmented by farmed mussels and oysters.