oldest

http://www.npr.org/blogs/krulwich/2013/01/10/169047159/the-oldest-rock-in-the-world-tells-us-a-story?utm_source=NPR&utm_medium=facebook&utm_campaign=20130111 Earth was only 150-300 million years old and it formed in liquid water... Exciting stuff if you understand the implications.

The world's oldest undeciphered writing system, which has so far defied attempts to uncover its 5,000-year-old secrets, could be about to be decoded by Oxford University academics. This international research project is already casting light on a lost bronze age middle eastern society where...

The Indus valley civilization and the Sumarian civilization are the two oldest civilizations that come to my mind at the moment. Can you mention some more old civilizations in the world?