This strategic fortification, the pivot of the Landport fortifications, situated to the north of the City of Gibraltar, was a key element in the overall defences of the garrison. In the present day, this bastion is surrounded by reclaimed land to the west and north with its main role originally having been to provide flanking fire across the barrier facing north towards Spain. It runs along Glacis Road, its former glacis, and Smith Dorrien Avenue which separates it from the curtain wall with the Giralda Gardens and the Gibraltar Petanca Association occupying its northwest corner.
The North Bastion was constructed over the much earlier medieval Moorish and Spanish era walls; in 1309, a tower was set up by the Castilians in the northwest end of it, later known as the Giralda Tower, in order, partly, to protect the arsenal. In the mid-16th century, the Lombardian military engineer, Giovan Giacomo Paleari Fratino (known as Il Fratino), was commissioned by King Philip II to improve the Rock’s defences; among the works carried out at the time was the conversion of the existing Giralda Tower into a bastion.