The western boundary of Madrid’s historical core consists of a series of monuments and squares: the Royal Palace (Madrid became the royal residence in 1561) by architect Giovanni Battista Sacceti from Torino built between 1737 and 1760 with the Plaza Armeria interior square and the Almudena cathedral, which was built over no less than one hundred years, from 1883 to 1993. The position of these monuments is striking since they are situated on the edge of a plateau from which the terrain slopes steeply towards the Royal Gardens – Campo del Moro and the river Manzanares.