Fort Santa Cruz was built between 1577 and 1604 by the Spaniards on the Pic d'Aidour above Gulf of Oran in the Mediterranean Sea, at an elevation of above 400 metres (1,312 ft).

[1][2][3][4] The fort is located at a height of about 400 metres (1,300 ft) on Mount Murdjadjo [fr], also known as Pic d'Aidour, from where there are views of Mers-el-Kebir, the strategic military port of Oran.

Notable in this regard was when Moroccan Sharif Moulay Ismail tried to force his way past the defenses in 1707, only to see his army decimated.

To show their dominance of "Crescent above the Cross", the local people built the Marabut chapel, opposite to the fort at a higher elevation.

[8] The fort, built between 1577 and 1604, The fortifications of the place were composed of thick and continuous walls of over two and a half kilometers in circumference, surmounted by strong towers spaced between them, with a central castle or kasbah where the Spanish governor established his headquarters.

The fort was built with iron, wood, sand, lime and water carried up the hill through winding and difficult paths.

In commemoration of this event, every year until Algeria became independent in 1962, Ascension Day was observed when the people of Oran and the surrounding areas paid homage to the Virgin Mary by climbing up the mountain trail to the chapel as a pilgrimage.