The Fort of San Diego in Algeciras was a military installation built around 1730 as a result of the policy of fortification of the area near Gibraltar undertaken by the government of Spain .

These forts prevented British ships from taking shelter in the harbour.

This was an important landmark with the Fort Punta Carnero which was located north of this position.

The British destroyed the Spanish fortifications around Gibraltar in to deny their use by Napoleon's forces.

The main Spanish lines were destroyed by Colonel Sir Charles Holloway on 14 February 1810 to the satisfaction o crowds who had come to see the spectacle.