The rampart wall is the fourth belt of Olivenza; almost nothing remains of the second and third belts. Built in the 17th century, it suffered three major sieges during the War of Restoration. This conflict arose between Portugal and Spain because the Portuguese refused to accept the rule of the kings of Spain, which began in 1580. The uprising against King Felipe IV and the subsequent appointment of its own king triggered a conflict that lasted from 1640 to 1668.
The Dutch Jesuit engineer Cosmander, who worked for the Portugese crown, designed it. Gilot, a French engineer with the recommendation of Descartes, also worked on the fortification of Olivenza. Both engineers died on this site for different reasons, but related to the sieges.
Most of the original nine bastions are preserved. Some of them have been redesigned for other uses such as the 19th century bullfighting ring and a modern-day auditorium. Of the three gates, only the monumental Calvary gate has been preserved.
Its defence was always very compromised since, in order to preserve some neighbourhoods, its layout was irregular and its nine bastions were excessive in number, which meant the commitment of "time, expense and many people for the garrison” (Marinho de Azevedo, 1644).