Great Zimbabwe is an extensive ruin in Eastern Zimbabwe. Wikipedia states it occupies an area of 2.7 square miles and at its peak was occupied by 10,000 people. It was built in the 11th to 14th centuries by the ancestors of the modern day Shona. In 1990 when we visited it it lay at the centre of a dry treeless area vegitated by sparse thorny scrub.
Things had been different in the past. Finds of blue glass trade beads suggested trading links with Swahili traders in earlier years.