These fascinating building can pop their noses up over the surrounding rooftops in a most astonishing way for the unsuspecting traveler. They contain an oven, capable of firing the full range of pottery produced on the site. Around the oven is a series of fires to produce the heat, aided by a system of flues. All was arranged to provide either a downdraught or an updraught but from the outside it's often impossible to discern which due to the enveloping brick shell. That is called the "hovel" and taxed the skills of the bricklayers. These had no fixed pattern to adhere to, so there can be considerable variation between the kilns.
   However, they all assume a general bottle shape, hence their name, irrespective of whether they fired pottery bottles or not. They were built in groups for ease in tending the fires. The workshops are close by and on one or maybe two levels, for greatest safety when transferring the soft clay from one stage to the next. Such kilns withstood the heating and cooling for twenty or thirty years and were then rebuilt. By the Second World War they were being superseded by more advanced technology, but fortunately some are being preserved.