Round towers at the time of King Phillip were a major innovation in castle construction. A round tower required less stone than a square tower, was more resistant to blows and besieging and had no hidden angles in shooting. At the Chateau de Druyes, the towers at each of the four corner lie mostly outside of the path of the wall, allowing a more effective visual scan of the base of walls and minimizing the threat of undermining. The south towers that frame the house, named the Sault and Beauregard towers, are the highest at 15 m. These 6 m diameter towers were accessed through the court as well as through the first floor of the house. They were probably covered by a battlement-style terrace, and the domed roofs were later replaced with pepperpot-style roofs. One domed roof still remains in good condition. The lower North towers were not accessible from the court, acting more as niches in the wall. The gatehouse is a square tower and the tallest tower of the castle at 20 m. It was placed in the middle of the north curtain wall. It is the only gate of the enclosure and was protected by a wooden gate outside, and a double door from the inside. It was reinforced by buttresses whose lower part has been made more massive later. Unlike the rest of the castle, masonry was of good quality, medium-sized brick. The gatehouse acted not only as an important defensive component of the keep, but also as a symbol of feudal power and stately residence. The first floor was a command room: it controlled access to the parapets of the curtain wall with two doors, allowing it to operate the gate as well defended the passage under the porch with three murder-holes. Access from the courtyard was by ladders that were removed in case of siege in order to keep the tower relatively isolated. The second floor was accessed by an internal wooden staircase which housed the winch and the portcullis mechanism. A stone staircase built within the thickness of the wall leads to the terrace. The battlements were not installed until later, probably at the same time as the installation of the postern of the town. In 1762, the battlements were replaced by a wall of large windows and covered with a Classical cornice and a hipped roof. Wishing to have a belfry, the villagers of Druyes obtained authorization of the Marquis of Anlezy to install a clock on the tower and a bell bearing the words: "I belong to the town of Druyes and I have been made at their expense."