The fortifications of the Cottonera Lines or as they are also known the Valperga Lines were built in the 17th and the 18th centuries to defend the Three Cities of Birgu, Bormla, and Isla from an enemy’s attack. The Cottonera Lines were proposed because there were fears of an Ottoman attack, therefore a new fortification was needed to defend the inner harbour area. The new fortifications were named Cottonera Lines after the Grand Master of the time Nicholas Cottoner. They were designed by the Italian engineer Antonio Maurizio Valperga and were meant to cater for up to 40 thousand people and their animals. Today, the Cottonera Lines have been included on the Antiquities List of 1925.