One World - Protecting the most significant buildings, monuments and features of Valletta (105)

The so called fosse or grain silos were dug in the rock at the time of the Order as part of the military strategy to store grain for use in case of a siege.

The fossos are bell-shaped reservoirs, each covered with a large stone cap, some circular; others sqaurish, carefully sealed with mortar when full of wheat, thus serving the purpose to store grain in a dry environment and easy to access. The surface between each capstone is covered in stone slabs.

Under the reign of Grand Master Gregorio Caraffa (1680-1690), trade and commerce were upgraded owing to the introduction of a sound infrastructural program. He created a number of large underground silos, mainly in the space in front of Fort St Elmo and Auberge de Castille. The fosses were managed by the Universita' dei Grani, whose headquarters, the Annona was next to St James Cavalier.

Seventy other silos were at the east end of Republic Street, near Fort St Elmo, but only about thirty still survive here. Seventy-five of these fosse can be seen at The Granaries in Floriana and which were constructed by the British in the 19th century. Some other silos are found at Pjazza Robert Sammut in Floriana. In front of Auberge de Castille were 15 other grain silos but these were covered by tarmac when the space in front of Auberge de Castille was landscaped. Valletta's fossos enabled the French to delay their surrender during the blockade of 1798-1800.

Mepa scheduled the Granaries at St Elmo as a Grade 1 national monument as per Government Notice No. 276/08 in the Government Gazette dated 28 March 2008.