The fashion for polygonal keeps began towards the end of the twelfth century (1160 onwards). The trend for this new type of keep began in Europe and was soon copied in England by Henry II. Polygonal castles were designed to overcome some of the problems with the square versions. Because there are many more sides there are less blind-spots meaning defenders could see attackers approaching from any angle. Polygonal keeps are more difficult to undermine. Most of these keeps are roughly circular or geometric in shape. Some are hexagonal or even octagonal. Some have enlarged buttresses into which rooms and staircases are built. As with square keeps polygonal keeps have the main halls at the centre of their designs.
Orford Castle, Suffolk
When seen from above the shape of the keep becomes apparent. A roughly circular core with three square turrets. The section at the bottom shows the position of the forebuilding with the main entrance and portcullis. The forebuilding extends only up to the first floor. The main staircase, shown as a segmented circle, extends from the basement to the top floor of the castle.
The lowest of the six floors is the basement and this was used for storage. There are two main halls in the keep and each hall spans two complete floors. Entrance to the keep is via a doorway with portcullis and lobby built into the forebuilding on the first floor. The chapel is located on the second floor above the main entrance, also built into the forebuilding.
These are the ground plans of Orford Castle. The black areas indicate solid walls and the white areas indicate rooms. Each floor has one central circular room with small corridors and chambers built into the surrounding masonry. The first image shows the layout of the ground level floor which was used for storage. In the centre of the ground floor room are the remains of a well that provided the castle's occupants with their water. The small rectangular room at the bottom of the plan at the base of the forebuilding is the dungeon with a toilet and ventilation. The small segmented circle shows the position of the spiral staircase. This staircase provides the only access of the ground level floor.
Inside Orford castle are two large halls, one on top of the other. Each hall spans two floors of the castle. These two plans show the layout of the two floors that make up the first large hall. The only entrance to the castle is shown at the bottom of the first plan along with the steps that lead up to the doorway. The doorway and lobby is built into the forebuilding. The large room on the second floor is the chapel.
These two plans show the arrangement of chambers and corridors leading from the upper of the two main halls. Again the upper hall spans two floors.