The famous Leaning Tower of Pisa was never straight. Construction began in 1173, but the tower started to lean just five years later when it was only three stories tall. The problem was the foundation. It was only three-meters deep and built on weak, unstable subsoil. The name 'Pisa' itself is believed to come from a Greek word for 'marshy land'. Just as the tilt became obvious, construction was halted for almost 100 years due to a series of wars between Pisa and other Italian city-states. This