Goodall described Warkworth's keep as "a masterpiece of medieval English architecture".
Built in the last quarter of the 14th century, it was probably designed by John Lewyn.
It was laid out in the form of a Greek cross and originally it was crested with a battlement, and perhaps decorative statues.
Around the top of the building survive carvings of angels carrying shields.
A large lion representing the Percy's coat of arms overlooked the town from the north side of the keep.
The lion and sculptures were probably originally painted and would have stood out from the rest of the building.
Archaeologist Oliver Creighton suggests that the rebuilding of the keep and other reconstruction work were meant to suggest the enduring lordship of the owners.
On top of the keep is a lookout tower, which would have been less prominent before the keep's roof was removed.


Goodall suggests that the keep was used only for short periods, and the west range, including the great hall, was the lord's preferred residence for prolonged visits to Warkworth Castle.
The ground floor was used predominantly for storage of food and wine, but there was also a room with access to a basement chamber roughly 9 feet (2.7 m) square.
This has variously been interpreted as an accounting room with a floor safe, or guardroom with a dungeon dug into the floor.
In the keep's west wall was a postern through which stores would pass into the building.
Kitchens occupied the west side of the first floor and were connected via staircases to the stores immediately below.
In the south-east corner was a great hall, originally heated by a central hearth and spanning the height of the first and second floors.
A chapel off the great hall led to a large formal room where the lord would meet guests.
The second floor was entirely domestic in nature, with bedrooms and withdrawing chambers.
In the 19th century, while the rest of Warkworth Castle was in ruins, the rooms of the second floor were re-roofed and occasionally used by the duke on visits.
At the centre of the keep was a lightwell with interior windows; at its foot was a tank for collecting rainwater used for cleaning.
Goodall described Warkworth's keep as "a masterpiece of medieval English architecture". Built in the last quarter of the 14th century, it was probably designed by John Lewyn. It was laid out in the form of a Greek cross and originally it was crested with a battlement, and perhaps decorative statues. Around the top of the building survive carvings of angels carrying shields. A large lion representing the Percy's coat of arms overlooked the town from the north side of the keep. The lion and sculptures were probably originally painted and would have stood out from the rest of the building. Archaeologist Oliver Creighton suggests that the rebuilding of the keep and other reconstruction work were meant to suggest the enduring lordship of the owners. On top of the keep is a lookout tower, which would have been less prominent before the keep's roof was removed.

Goodall suggests that the keep was used only for short periods, and the west range, including the great hall, was the lord's preferred residence for prolonged visits to Warkworth Castle. The ground floor was used predominantly for storage of food and wine, but there was also a room with access to a basement chamber roughly 9 feet (2.7 m) square. This has variously been interpreted as an accounting room with a floor safe, or guardroom with a dungeon dug into the floor. In the keep's west wall was a postern through which stores would pass into the building. Kitchens occupied the west side of the first floor and were connected via staircases to the stores immediately below. In the south-east corner was a great hall, originally heated by a central hearth and spanning the height of the first and second floors. A chapel off the great hall led to a large formal room where the lord would meet guests. The second floor was entirely domestic in nature, with bedrooms and withdrawing chambers. In the 19th century, while the rest of Warkworth Castle was in ruins, the rooms of the second floor were re-roofed and occasionally used by the duke on visits. At the centre of the keep was a lightwell with interior windows; at its foot was a tank for collecting rainwater used for cleaning.
Warkworth Castle