sentences:  Its walls are thick at the base, with a core of flint stone, faced on the inside and outside with brick; the archaeologist T. P. Smith considers it to feature some "of the finest medieval brickwork" in England.The walls have gunports for the smaller pieces of artillery and the roof would have supported the heavier bombards, with wide embrasures giving the weapons adequate firing space.The Cow Tower was specially designed to support the use of gunpowder artillery, making it a very rare structure in England for this period