Brielle, also called Den Briel (Brill in English) is a town, municipality and historic seaport in the western Netherlands, in the province of South Holland, on the north side of the island of Voorne-Putten, at the mouth of the New Maas. Brielle is a very old, fortified town. Its name is derived from the Celtic word brogilo (meaning "closed area" or "hunting grounds"). The oldest writings about Brielle indicate that the current location is the "new" Brielle. Den ouden Briel (Old Brill) must have been situated somewhere else on the Voorne-Putten Island. It received city rights in 1306.