I came across this link on one Amazing News site or another:
Short version: there’s a network of ancient ruins in southern Africa, stretching from South Africa to Kenya. Their opening claim is that they represent the oldest surviving man made structures currently known, one of which appears to function as a calendar. Claims beyond that start rubbing the skeptical kitty the wrong way, beginning with the statement that these artifacts are 75,000 years old (or possibly older). It appears this site is almost brand new news: Googling “makomati” yields fewer than 1,000 results. Does anyone have the straight dope?