Seen in the 19th Century, these were a collection of small defensive forts built throughout England - although initially - Martello's could be found in Spain (and probably inspired British use). Constructed of stone and brick, a Martello stood about 40 feet high (with 8 foot thick walls) and were circular in design. They consisted of 2 floors. On the top (or roof level), artillery pieces could be installed and have a full 360 degree range of fire if need be. Some were actually made into “mini castles” with Towers and surrounding Moats erected. They were built in large amounts closer to the coastline. A “garrison” of 24 men could be stationed in a Martello. With the advent of improved cannon barrel rifling, the Martello's use was discontinued. They were pressed into service again, during World War II, as supply and materials storage areas. Many still survive today.