This era covers thousands of years with many different cultures and communities. The oldest evidence that point to inhabitants of the Peninsula is perhaps 63,000 years old. There are inhabitants that had trading relations with many parts of the ancient world, but the hot and harsh climate had made large settlements difficult. So bedouin groups were naturally also present. Some settlements had always existed around oases; these are places in the deserts where growth and water are available. For instance there was a culture called the Dilmun culture among them, which was very old and existed along the Persian Gulf. It was as old as the ancient civilizations of the Sumerians and Egyptians. But also the Kindite kingdom and other ancient communities were present.