The Granaries are situated in front of St Publius Church in Floriana. The location simply looks like a large open square, but beneath the numerous stone caps dotted around the square, are bell shaped grain storage silos, seventy six in total, capable of holding around sixty five tons of grain each.
Granaries are pits dug into the ground and covered by circular stone slabs. They were primarily used for the storage of Grain. Granaries can be found throughout Valletta and Floriana. The first granaries were built by the Knights of St John’s to provide for storage within the fortifications in case of a siege. As the system of storage was reliable and efficient, the British authorities copied in all details the Knights' granaries. The Granaries proved their worth as they continued to provide grain for the starving population during World War 2. The highest grouping of granaries (a total of 76) is found. The silos remained in use until 1962, when a modern above storage facility was built.
Granaries at Il-Fosos, now officially named Pjazza San Publiju, were not built by the knights as many believe. They were built by the British and are smaller than the ones in Valletta (St Elmo Place and Castille Place) and Floriana (St Anne Street and near the Capuchin Friary). The square is also one of the largest urban open spaces in Malta and is therefore use for mass gatherings. Nowadays, the square is used for concerts, festivals, mass meetings and national events.
One important gathering was held in May 1990 during Pope John Paul II's visit to Malta. During the second Papal visit on 9 May 2001, Pope John Paul II beatified three Maltese in this square, one of whom was eventually canonised (St Ġorġ Preca). As Malta is a predominantly Catholic country, this is considered to be an important event in Malta's history. A third papal visit took place on 18 April 2010 by Pope Benedict XVI. The Isle of MTV summer festival is among other major events held here annually.