Any freestanding or attached structure that is relatively tall in proportion to its base.
The Romans, Byzantines, and medieval Europeans built defensive towers as part of the fortifications of their city walls (e.g., the Tower of London ). Indian temple architecture uses towers of various types (e.g., the sikhara ). Towers were an important feature of churches and cathedrals built in the Romanesque and Gothic periods. Some Gothic church towers were designed to carry a spire ; others had flat roofs. The Italian campanile could either be attached to a church or freestanding. The use of towers declined somewhat during the Renaissance but reappeared in Baroque architecture . The use of steel frames enabled buildings to reach unprecedented heights; the Eiffel Tower in Paris was the first structure to reveal the true vertical potential of steel construction.