Economy of Valletta

Buildings of historic importance include St John's Co-Cathedral, formerly the Conventional Church of the Knights of Malta. It has the only signed work and largest painting by Michelangelo Merisi da Caravaggio. The Auberge de Castille et Leon, formerly the official seat of the Knights of Malta of the Langue of Castille, Léon and Portugal, is now the office of the Prime Minister of Malta. The Magisterial Palace, built between 1571 and 1574 and formerly the seat of the Grand Master of the Knights of Malta, now houses the Maltese Parliament and offices of the President of Malta.

The National Museum of Fine Arts is a Rococo palace dating back to the late 1570s, which served as the official residence of the Commander-in-Chief of the Mediterranean Fleet during the British era from 1789 onwards. The Manoel Theatre (Maltese: Teatru Manwel) was constructed in just ten months in 1731, by order of Grand Master Antonio Manoel de Vilhena, and is one of the oldest working theatres in Europe. The Mediterranean Conference Centre was formerly the Sacra Infermeria. Built in 1574, it was one of Europe's most renowned hospitals during the Renaissance. The fortifications of the port, built by the Knights as a magnificent series of bastions, demi-bastions, ravelins and curtains, approximately 100 metres (330 ft) high, all contribute to the unique architectural quality of the city.

Public housing is located within Valletta's walls. Originally the Order planned to construct for its navy a man-made anchorage in the area known as Manderaggio (Maltese: il-Mandraġġ), but never completed this plan. Instead, the area became a jumble of buildings with dark alleyways. In the 1950s