Here is its location in Zimbabwe: http://imgur.com/9gi2nP8
Construction started in the 11th centure by the ancestors of the Shona people, and construction continued into the 15th century. The first mention of it I can find is in a entry from 1531 by the Captain of the Portugese garrison of Sofala "Vincent Pegado". He describes: "Among the gold mines of the inland plains between the Limpopo and Zambezi rivers there is a fortress built of stones of marvelous size, and there appears to be no mortar joining them.... This edifice is almost surrounded by hills, upon which are others resembling it in the fashioning of stone and the absence of mortar, and one of them is a tower more than 12 fathoms high. The natives of the country call these edifices Symbaoe, which according to their language signifies court." So it was first recorded as being named "Symbaoe".
It is built on a granite outcropping, and the outer walls consist of almost a million granite blocks assembled to fit together perfectly without mortar.
Research through the 1960s and 1970 was heavily disputed. The govornment of Rhodesia insisted the structure was built by non-blacks. Paul Sinclair states: "Once a member of the Museum Board of Trustees threatened me with losing my job if I said publicly that blacks had built Zimbabwe. He said it was okay to say the yellow people had built it, but I wasn't allowed to mention radio carbon dates... It was the first time since Germany in the thirties that archaeology has been so directly censored." Fortunately the truth wasn't covered up, and it is now widely accepted to have been built by people of the Gokomere culture.
An overview of the Great Enclosure: http://farm5.static.flickr.com/4117/4794987924_9c98f40d98_b.jpg
The outer wall of the Great Enclosure: https://lh3.googleusercontent.com/-_89UaCLAU6Y/UDucohy5XbI/AAAAAAAABDk/fPBQv9G-_x4/s1152/4795002226_ec27dabd80_o-2.jpg
Walls showing that no mortar was used in their construction: http://farm6.staticflickr.com/5537/11438068186_353058a5bb_c.jpg
Walls built to the terrain: http://farm7.staticflickr.com/6094/6262488484_43ae48f218_b.jpg http://farm5.staticflickr.com/4102/4794994924_44ff00f820_b.jpg http://farm6.staticflickr.com/5518/11438098946_1b0d3701ae_c.jpg
Very narrow corridors between the walls: http://farm6.staticflickr.com/5534/11438066544_e718c332ca_c.jpg http://farm6.staticflickr.com/5083/5209296982_c9d2336368_b.jpg http://upload.wikimedia.org/wikipedia/commons/d/d6/Great_zimbabwe_2.jpg
The top of the walls: http://farm5.staticflickr.com/4036/4371938199_ab93986436_o.jpg
The conical tower: http://upload.wikimedia.org/wikipedia/commons/9/9e/Great_Zimbabwe_%28Donjon%29.jpg
A stone lintel above a doorway: http://upload.wikimedia.org/wikipedia/commons/6/6e/Zimbabwe_stone_lintel.jpg
More remains: http://interhdb.com/media/k2/items/cache/1fc372946c0b98fb8d7f87d4c38ea83a_XL.jpg
