Outer Defenses of Stirling Castle, Stirling

The Outer Defenses of Stirling Castle represent a complex system of artillery fortifications, largely developed in their current form during the 18th century. However, older elements, such as the French Spur on the east side, date back to the mid-16th century under the regency of Mary of Guise. The French Spur, originally an orillon (an ear-shaped bastion), featured gun emplacements to defend the main spur. This structure was fortified with a talus, and an earth ramp, and was accessible via a drawbridge over a defensive ditch. Excavations in the 1970s revealed that significant portions of the original stonework still exist beneath the later modifications.

In response to the Jacobite threat in 1708, enhancements to the castle's defenses became a priority. The military engineer Theodore Dury proposed a new defense plan, but this was met with criticism from Captain Obryan, who offered a more costly alternative. A compromise was ultimately implemented, and the new defenses were completed by 1714. These changes included the extension of the main front wall to create Guardhouse Square, which established a double line of defensive walls, both protected by ditches and caponiers (covered firing galleries). One of these caponiers remains accessible today via a narrow staircase from Guardhouse Square.

To bolster the defenses, casemates (chambers built behind the walls) were constructed, allowing for additional gun emplacements. Modifications to the French Spur permitted the installation of more cannons. Guardhouse Square itself was further developed in the 19th century, and just outside the castle lies the early 19th-century Esplanade, which was originally a parade ground and is now used for parking and public performances.