The garden of San Carlos was built as a defensive castle outside the city walls in the 14th century, and was joined to the city in the 16th century.

It gradually lost importance as a bastion and, after the explosion of the powder magazine it contained, it was abandoned until it was recovered as a garden by Carlos F. de Croix in the 18th century.

The current appearance of the garden of San Carlos is due to the governor Francisco de Mazarredo in 1834 and it has the characteristics of a romantic garden. It has been declared a Historic-Artistic Site together with the city walls.

Its value lies in its privileged location from where, thanks to its viewpoint, the whole of the port of A Coruña can be seen, in its vegetation, and in the tomb, a sepulchre designed as a funerary monument, of the Scottish general Sir John Moore, who died in the battle of Elviña in 1809 fighting while defending the embarkation of the English army against the French Napoleonic troops of General Soult.

Numerous species of both native and exotic trees are present in the garden, of which two gigantic centenary elm trees stand out.

There are also tribute plaques to the 172 officers and men of the English Royal Navy who died in the sinking of the ship "Serpent" near Cape Villano on 10 November 1890.

The building adjoining the gardens is the headquarters of the Archive of the Kingdom of Galicia, the most important historical archive in the community of Galicia.