Greater Zimbabwe was the capital of the Kingdom of Zimbabwe during the country’s later Iron Age. The monument first began to be built in the 11th century, and work continued until the 14th century. It covered an area of 722 hectares (1,780 acres) which might have housed up to 18,000 people. It was a royal city for the Zimbabwean monarch. One of its most prominent features were its walls, some of which were over five metres high and which were constructed without mortar. Eventually the city was abandoned and fell into ruin.