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                                         Fortifications 
                                        are military constructions and buildings 
                                        designed for defense in warfare. Humans 
                                        have constructed defensive works for many 
                                        thousands of years, in a variety of increasingly 
                                        complex designs. The term is derived from 
                                        the Latin fortis ("strong") 
                                        and facere ("to make"). Many 
                                        military installations are known as forts, 
                                        although they are not always fortified. 
                                        Larger forts may class as fortresses, 
                                        smaller ones formerly often bore the name 
                                        of fortalices. The word "fortification 
                                        " can also refer to the practice 
                                        of improving an area's defense with defensive 
                                        works. The art of laying out a military 
                                        camp or constructing a fortification traditionally 
                                        classes as castrametation, since the time 
                                        of the Roman legions. The art/science 
                                        of laying siege to a fortification and 
                                        of destroying it has the popular name 
                                        of siegecraft and the formal name of poliorcetics. 
                                        In some texts this latter term also applies 
                                        to the art of building a fortification.
                                        
                                        
                                        
                                        
                                        
                                        
                                        Bourtange 
                                        fortification, restored to 1750 situation, 
                                        Groningen (province), NetherlandsFortification 
                                        is usually divided into two branches, 
                                        namely permanent fortification and field 
                                        fortification. Permanent fortifications 
                                        are erected at leisure, with all the resources 
                                        that a state can supply of constructive 
                                        and mechanical skill, and are built of 
                                        enduring materials. Field fortifications 
                                        are extemporized by troops in the field, 
                                        perhaps assisted by such local labor and 
                                        tools as may be procurable, and with materials 
                                        that do not require much preparation, 
                                        such as earth, brushwood and light timber. 
                                        There is also an intermediate branch known 
                                        as semipermanent fortification. |  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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