An almost solid dry-stone structure with internal rooms and connecting chambers and typical of Shetland
An edifice or structure of heavy timbers or logs for military defense, having its sides loopholed for musketry, and often an upper story projecting over the lower, or so placed upon it as to have its sides make an angle wit the sides of the lower story, thus enabling the defenders to fire downward, and in all directions; formerly much used in America and Germany
Small square fortification, usually of timber bond overlapping arrangement of bricks in courses (flemish, dutch, french, etc )
A reinforced building from which to control hazardous operations, such as an explosion or a rocket launch