In ancient times, bitumen was primarily a Mesopotamian commodity used by the Sumerians and Babylonians, although it was also found in the Levant and Persia. Along the Tigris and Euphrates rivers, the area was littered with hundreds of pure bitumen seepages. The Mesopotamians used the bitumen for waterproofing boats and buildings. Ancient Persian tablets indicate the medicinal and lighting uses of petroleum in the upper levels of their society. In ancient Egypt, the use of bitumen was important in creating Egyptian mummies — in fact, the word mummy is derived from the Arab word "mūmiyyah", which means bitumen. Oil from seeps was exploited in the Roman province of Dacia, now in Romania, where it was called "picula".