Which civilization is worlds most ancient civilization?

Oldest known is Lemuria.

Lemuria is the oldest civilization in the world. According to various esoteric sources, civilization first appeared 78,000 years ago in the giant continent known as Mu or Lemuria and lasted for an astonishing 52,000 years. It is sometimes said to be the oldest civilization has been destroyed in earthquakes generated by a pole shift which occurred some 26,000 years ago, or about 24,000 BC. Lemuria is the oldest civilization.