sentences:  This "Plaza de Armas" was designed on a standard military fashion based on a grid pattern, taken from the Roman Castrum, of which one of the blocks would be left vacant to form the Plaza de Armas.It is often surrounded by governmental buildings, churches, and other structures of cultural or political significance.The name derives from the fact that this area would be a refuge in case of an attack upon the city, from which arms would be supplied to the defenders.