The collision of tectonic plates in Southwest Asia has created a landscape of mountains, plateaus, valleys, and narrow gulfs. The Tigris and Euphrates Rivers flow through the fertile Mesopotamia region between these landforms. The Persian Gulf region has plentiful oil reserves but limited water supplies, which countries obtain through desalination, wells, or ancient fossil water aquifers. Some of the world's earliest civilizations developed here, and it has been conquered by various empires throughout history including Akkadians, Persians, Ottomans, British, and Russians. The dominant cultures today are Arab, Kurdish, and Persian.