Fortifications are militaryconstructions designed for defensivewarfare. They have been used for many thousands of years, in a variety of increasingly complex designs. The practice of improving an area's defense is also known as "fortification". Many military installations are known as forts, although they are not always "fortified".
... exerciser device. Once the gyroscope inside it is going fast enough, for example after starting it with a short rip string or by a snap of the thumb, a person holding it in ...