Pelplin (ˈpɛlpljin; Pôłplëno; formerly German also: Pelplin) is a town in northern Poland, in the Tczew County, Pomeranian Voivodship. Population: 8,320 (2009). Pelplin is located in the ethnocultural region of Kociewie in Pomerania. It is home to one of the finest collections of medieval art in Poland held at the Diocesan Museum in Pelplin. It is known for the landmark Gothic Pelplin Cathedral, former abbey church, one of the largest Gothic churches in Poland. The former Pelplin Abbey is the seat of the Roman Catholic Diocese of Pelplin. The cathedral complex, with the abbey, theological seminary, Corpus Christi church, Episcopal Palace and Park, etc. is listed as a Historic Monument of Poland, as one of the most precious Polish heritage sites of its kind. Pelplin lies in a valley on both sides of river Wierzyca, a left affluent of river Vistula in Pomeralia, which ends up in the Vistula at the town of Gniew. Pelplin is located about west of the Vistula, south-east of the town of Starogard Gdański, south-west the town of Tczew and south of the regional capitol of Gdańsk. It is surrounded by a chain of little hills, its altitude varies between above sea level at the lowlands of the Vistula in the east and above sea level at 'Czubatka' hill in the west. Archaeological findings have revealed that human settlements existed in the region of the town already during the Stone Age and the Bronze Age. The history of Pelplin is tightly interwoven with the history of the Monastery of Pelplin, which according to the monastery's chronicle was founded in 1274 by Mestwin II, Duke of Pomerania. The monastery of Pelplin had a forerunner in the monastery of the Cistercians in Pogódki located at the upper course of the Wierzyca, which had been founded in 1258 by Sambor II, Duke of Pomerania. In 1276 the monks, which had come from the Monastery of Doberan in Mecklenburg to Pogódki, began to transfer their monastery to Pelplin. From Pelplin, the German monks organized an extensive settlement campaign.