Why this local preference for the cylindrical? Explanations range from the absurd to the mechanistic. Some believe these towers are the shafts of ancient wells that were exposed when a flood washed away the ground. Others, with only a little less magic mushroom in their diet, dream up connections with pagan worship, fancying that these fingers to the sky mark the sites of ancient circles. Some point to the round towers of Ireland and Scotland and argue that, because these were primarily defensive structures, the East Anglian examples must also have been places of refuge. However, given that all they have in common is their roundness, this is a circular argument if ever there was one. This is why the guidebooks and brochures all talk of "quoins".
Quoins (pictured top right) are what architects call the squared stones that masons place at the corners of rectangular buildings to provide strength and stability. In East Anglia, there is little stone from which to carve quoins. No quoins, no angles, says the argument. No angles, no square towers. It's an accepted fact - or is it?
Recent research suggests that East Anglians built round towers for reasons more to do with culture than construction. After all, the churches to which the towers are attached generally had square corners. If they could build rectangular churches, why not square towers? The most likely answer lies over the North Sea, in Lower Saxony and Schleswig Holstein. There, it seems, round towers were all the rage, despite the availability of good stone. For the style to spread from Northern Germany to Eastern England, it had only to follow well-established trade routes. In other words, round towers were fashionably "continental", while square towers were just that - square.