Berck, sometimes referred to as Berck-sur-Mer, is a commune in the Pas-de-Calais department in northern France. It lies within the Marquenterre regional park, an ornithological nature reserve.GeographySituated just to the north of the estuary of the river Authie, Berck has a huge expanse of sandy beach and impressive grassy-topped dunes facing north onto the English Channel. The town comprises two parts – to the east, the old fishing town of Berck-Ville and to the west the seaside area, Berck-sur-Mer.ToponymyBerck is attested along the centuries with various forms: datum Bergis and/or Berc in 1215, Bierk in 1282.Its origin has been conjectured to come either from Germanic berg "hill", "mount" or birkja "place of the birch trees", designating the birch tree wood nearby. The Modern Dutch word for "birch" is berk.In Dutch Berk-aan-Zee.HistoryThe old town was formerly a fishing harbour which in 1301 was recorded to have 150 homesteads with 800 inhabitants. A mediaeval wooden lighthouse, known locally as a foïer, was built on a dune and lit by charcoal and faggots but this burned down several times. On one occasion at least it was as a result of the continuous conflict between the English and the French in the Hundred Years War. The chronicler Enguerrand de Monstrelet mentions that during 1414 the English garrison in Calais raided south and burned the town. Eventually the lighthouse was replaced by a stone tower at the side of which a chapel was built in the 15th century, but this did not save it from further mishap. During the second siege of Montreuil in 1544, the English advanced from the south and burned 200 houses, the church and the mill as they passed through Berck. What was left of the place was then burned by the French on their way to relieve the siege.