The gate towers of the northern forecastle
Built along with the northern forecastle during the 15th century. The entrance gate was once between the two towers. Together with a moat and drawbridge, they made up the defensive system of the castle from the North. The towers were dismantled during the 17th century. Archaeological work was done there in 1968 and 1978. The foundations of the smaller tower have been preserved, and the large tower has been partly restored.
The forced passage
This passage was built together with the northern forecastle. It was part of the unified defensive system and meant that if an enemy broke through the gates of the northern forecastle, it found itself in a narrow passage with stone walls. The internal gate tower concluded the passage, which was examined in the early 1980s. The eastern wall of the passage was conserved during the 1990s.
The internal gate tower
The tower was built in the early 16th century as a cannon tower. It was the largest tower in terms of diameter, and its purpose was to protect the central part of the castle from the North and the western defensive wall from the flanks. The tower was dismantled during the first half of the 17th century and underwent archaeological examination in 1982 and 1983. A project has been drafted on the conservation and restoration of the tower.
The location of the redoubt
After the northern forecastle was torn down in the 17th century, access to the castle from the North was protected by earthen ramparts or a redoubt. A cellar was installed in place of the redoubt in the 19th century, and archaeological work was done here in the early 1980s.