The design of the Fortress of Mazagan is a response to the development of modern artillery in the Renaissance. The star form of the fortress measures 250m by 300m. The slightly inclined, massive walls are 8m high on average, with a thickness of 10m, enclosing a patrolling peripheral walkway 2m wide. At the present time the fortification has four bastions: the Angel Bastion in the east, St Sebastian in the north, St Antoine in the west, and the Holy Ghost Bastion in the south. The fifth, the Governor’s Bastion at the main entrance, is in ruins, having been destroyed by the Portuguese in 1769. Numerous colonial-era Portuguese cannons are still positioned on top of the bastions.

The Portuguese Fortified City of Mazagan was registered as a UNESCO World Heritage Site in 2004, on the basis of its status as an "outstanding example of the interchange of influences between European and Moroccan cultures" and as an "early example of the realisation of the Renaissance ideals integrated with Portuguese construction technology".

El Jadida (Berber: ⵎⴰⵣⵖⴰⵏ Mazghan, Arabic:الجديدة "new") is a port city on the Atlantic coast of Morocco, in the province of El Jadida. It has a population of 144,440. From the sea, El Jadida's old city; has a very "un-Moorish" appearance; it has massive Portuguese walls of hewn stone. El Jadida, previously known as Mazagan (Portuguese: Mazagão), was seized in 1502 by the Portuguese, and they controlled this city until 1769, when they abandoned Mazagão. Its inhabitants were evacuated to Brazil, where they founded new settlement Nova Mazagão (now in Amapá). El Jadida was then taken over by Sultan Mohammed ben Abdallah.

According to UNESCO, the most important buildings from the Portuguese period are the cistern, and the Manueline Church of the Assumption. The design of the Fortress of Mazagan is a response to the development of modern artillery in the Renaissance. The star form of the fortress measures c 250m by 300m. The slightly inclined, massive walls are c 8m high on average, with a thickness of 10m, enclosing a patrolling peripheral walkway 2m wide. At the present time the fortification has four bastions: the Angel Bastion in the east, St Sebastian in the north, St Antoine in the west, and the Holy Ghost Bastion in the south. The fifth, the Governor’s Bastion at the main entrance, is in ruins, having been destroyed by the Portuguese in 1769. Numerous colonial-era Portuguese cannons are still positioned on top of the bastions.