The Great Bulwark was built in the 1490s. This early artillery fort, along with the Munot in Schaffhausen (1563), is the only structure of this kind in Switzerland.
In Fribourg, it is the last of three built on the vulnerable north and west sides of the city. It is made up of a tower called "Curtils Novels" (New Gardens) that was built in 1400 and the actual bulwark, originally built of wood in the 1440s and rebuilt in large sandstone blocks with great technical mastery shortly before 1500. In the seventeenth century, the cannon embrasures were enlarged for bigger guns. Shaped like an upside-down U, the bulwark is approximately 35 metres wide and the space inside is divided floor-wise into two wooden galleries.