His Majesty's Naval Base, Portsmouth is one of three operating bases in the United Kingdom for the Royal Navy. Portsmouth Naval Base is part of the city of Portsmouth; it is located on the eastern shore of Portsmouth Harbour, north of the Solent and the Isle of Wight. For centuries it was officially known as HM Dockyard, Portsmouth: as a Royal Navy Dockyard, Portsmouth functioned primarily as a state-owned facility for building, repairing and maintaining warships; for a time it was the largest industrial site in the world.