The Lisbon Naval Base is the main installation and operational base of the Portuguese Navy. Located at the former Royal Estate of Alfeite on the south bank of the Tagus river's estuary, near the city of Almada, the installation is sometimes referred to as the Alfeite Naval Base.Most of the Portuguese Naval fleet ships are based at Alfeite, as well as many of its administrative, training and support services. Within its perimeter are also located the Naval School, the Naval Technologies School, the Alfeite Arsenal, the Marine corps Base and other Portuguese Navy units.