Windmills became prevalent in Europe between the 11th and 14th centuries. The most suitable environment for their construction was to be found in the foothills of mountains, on plains and in coastal landscapes, where strong air currents abounded. They were generally wooden post mills, standing on a characteristic conical trestle log base. They would be rotate around the central stake to face into the wind. As a rule, the mill had four vanes - sails set in a rectangular cross mounted on the front wall of the building. As the wind leant into them, they would turn to move a wooden gearing and transfer the torque to the millstones, located on the first floor. The disadvantage of windmills was their frequent need for repair and maintenance, and they were often struck by lightning. When operating, they vibrated intensely, making working in them neither pleasant nor safe.