
The fortifications of Birgu are a series of defensive walls and other fortifications which surround the city of Birgu, Malta. The first fortification to be built was Fort Saint Angelo in the Middle Ages, and the majority of the fortifications were built between the 16th and 18th centuries by the Order of Saint John. Most of the fortifications remain largely intact today.

The Cittadella, also known as the Castello, is the citadel of Victoria on the island of Gozo, Malta. The area has been inhabited since the Bronze Age, and the site now occupied by the Cittadella is believed to have been the acropolis of the Punic-Roman city of Gaulos or Glauconis Civitas.

The Cottonera Lines, also known as the Valperga Lines, are a line of fortifications in Cospicua and Birgu, Malta. They were built in the 17th and 18th centuries to form the outer defences of the Three Cities of Birgu, Senglea and Cospicua. They surrounded an earlier line of fortifications, known as the Santa Margherita Lines.

The Floriana Lines are a line of fortifications in Floriana, Malta, which surround the fortifications of Valletta and form the capital city's outer defences. Construction of the lines began in 1636 and they were named after the military engineer who designed them, Pietro Paolo Floriani. The Floriana Lines were modified throughout the course of the 17th and 18th centuries, and they saw use during the French blockade of 1798–1800. Today, the fortifications are still largely intact but rather dilapidated and in need of restoration.

The fortifications of Mdina are a series of defensive walls which surround the former capital city of Mdina, Malta. The city was founded as Maleth by the Phoenicians in around the 8th century BC, and it later became part of the Roman Empire under the name Melite. The ancient city was surrounded by walls, but very few remains of these have survived.

The Santa Margherita Lines, also known as the Firenzuola Lines, are a line of fortifications in Cospicua, Malta. They were built in the 17th and 18th centuries to protect the land front defences of the cities of Birgu and Senglea. A second line of fortifications, known as the Cottonera Lines, was later built around the Santa Margherita Lines, while the city of Cospicua was founded in the 18th century within the Santa Margherita and Cottonera Lines.

The fortifications of Senglea are a series of defensive walls and other fortifications which surround the city of Senglea, Malta. The first fortification to be built was Fort Saint Michael in 1552, and the majority of the fortifications were built over the next decade when it was founded by Grand Master Claude de la Sengle. Modifications continued until the 18th century, but large parts of the fortifications were demolished between the 19th and 20th centuries. Today, all that remain of Senglea's fortifications are the seaward bastions and part of the land front.

The fortifications of Valletta are a series of defensive walls and other fortifications which surround the capital city of Valletta, Malta. The first fortification to be built was Fort Saint Elmo in 1552, but the fortifications of the city proper began to be built in 1566 when it was founded by Grand Master Jean de Valette. Modifications were made throughout the following centuries, with the last major addition being Fort Lascaris which was completed in 1856. Most of the fortifications remain largely intact today.