Civilization Collapse, The Great Zimbabwe

15th CenturyAfrica

"The Great Zimbabwe is the most famous of a large group of stone-walled enclosures on the Zimbabwean plateau. The modern Zimbabwe nation took its name from this major cultural monument...At its height in the 13th century, Great Zimbabwe's capital was home to as many as 18,000 people. Subsistence to support such population concentrations remained crucial, and it is likely that cattle and agricultural surplus played a highly visible role in the maintenance of power. The collapse of the Great Zimbabwe occupation is dated to the mid- to late 15th century, when most of the site was abandoned. Reasons posited for Great Zimbabwe's collapse have included the possible exhaustion of local gold, arable land, or water resources, and the disruption of the Indian Ocean trading sphere by the Portuguese. "

'The Great Zimbabwe, ancient ruins', Frank and Frances Carpenter Collection, between 1890 and 1925.

http://www.pbs.org/wonders/Episodes/Epi6/6\_wondr1.htm