Guarding the entrance to both Marsamxett and Grand Harbours is Fort St Elmo, named after the patron saint of mariners. Although now much altered, this fort was built by the Knights in 1552 in a mere four months to guard the harbours on either side of the Sceberras Peninsula, and was the fort that bore the brunt of Turkish arms during the Great Siege of 1565. After restoration and renovation, the fort opened to the public in 2015, containing the stunning National War Museum.
The courtyard outside the entrance to the fort is studded with the lids of underground granaries. You can visit the parade ground, and the 1559 chapel where Knights fought to the death during the siege trying to protect the altar, as well as the later 1729 church.
In Guardia is a colourful and photogenic military pageant in 16th-century costume, which includes a cannon-firing demonstration. Check upcoming dates at the tourist office.