A top a plateau in southern Zimbabwe stand the crumbling remains of a stone city that has intrigued scholars since its discovery in the late 1800s.
Local tribesmen call the massive granite stoneworks "Zimbabwe," which means "venerated houses" or "stone houses" in the Bantu language, but nobody knows who built them, when or why.
European scholars theorized the ruins had been constructed by some advanced civilization far to the north, possibly the Phoenicians or Egyptians. Another suggestion was that "Great Zimbabwe," as the ruins came to be known, may have been the site of King Solomon's legendary mines.
Scattered over 60 acres, the complex is dominated by a huge, walled enclosure dubbed the "Acropolis" because of its hilltop site. Three different structures are included in the complex - a majestic, fortress-like series of walls, labyrinthine passages, steps and corridors; a magnificent temple in another walled enclosure more than 100 yards long and 70 yards wide; and a series of lesser buildings, known simply as the Valley Ruins.
German archaeologist Karl Mauch came upon the imposing formations while tracking through the bush in 1871.
The discovery stimulated interest in long-lost cities and civilizations. Soon waves of archaeologists and tourists were flocking to what was then called Rhodesia to investigate and marvel at Great Zimbabwe's brooding temples and circular walls and soaring towers.
Experts believed the ruins were a by-product of the gold trade that flourished in the region thousands of years ago. Most scholars supported Mauch's theory that Great Zimbabwe had been planned and built as a trading post by skillful architects and workmen imported from either Egypt or Phoenicia.
But could the African Acropolis really have been built thousands of years ago? To many archaeologists this seemed doubtful, especially after a Scottish expert, David Randall-MacIver, concluded that the stone structures were only hundreds instead of thousands of years old, and that they were the work not of foreign workers but of Africans.
These findings, announced early in this century, were upheld by an English archaeologist, Gertrude Caton-Thompson, who, in 1929, wrote: "... examination of all the existing evidence, gathered from every quarter, still can produce not one single item that is not in accordance with the claim of Bantu origin and medieval date."
Zimbabwe's age continued to be debated, but evidence found in deposits dated by carbon-14 analysis suggests that work on the Acropolis, the earliest settlement on the hill, did not begin until the second or third century A.D. By around 1200 the area was controlled by the ancestors of the present Shona people, the Mbire, who were skilled miners, craftsmen and traders, and who formed a well-organized political entity.
When and why was the flourishing trading and religious center of Great Zimbabwe abandoned?
Historians are now fairly certain that by the start of the 16th century, the inhabitants of the ancient city simply ran out of food and timber supplies. Climatic changes, such as a series of droughts and crop failures, could have sent the population fleeing, or even a disastrous epidemic that might have wiped out cattle and game.
Inter-tribal warfare has also been listed as a possible cause for the city's sudden and complete abandonment.
Whatever the cause, Great Zimbabwe slowly declined until nothing was left but the crumbling gray walls that brood over the silent valley.
Randall Floyd is a professor of history at Augusta State University and a syndicated writer.