Southwest Asia is comprised of urban pockets as well as expansive land masses, most notably the Arabian Desert and East Sahero-Arabian Xeric Shrublands, which combined make up the most continuous body of sand in the world. Cutting through Saudi Arabia is the Tuwayq escarpment, an arc of limestone cliffs, caves and canyons that stretches nearly 500 miles. The Rub’al-Khali, a sedimentary basin, stretches from Saudi Arabia to Oman and Yemen.
Salt flats exist in some areas of the desert, as well as quick sands. A great deal of southwest Asia is considered to be hyper-arid, meaning that times have been recorded where there is no rain for 12 consecutive months. The area is bordered by Europe in the northwest, and the Mediterranean Sea on the western coastline of the region. Other bodies of water in or bordering the area include the Sea of Marmara, Bosporus Strait, the Black Sea and the Caspian Sea.
Most commonly called the Middle East, southwest Asia is most notable for its vast territories. Countries that make up this region include Turkey, Saudi Arabia, Iran, Israel, Iraq, United Arab Emirates, Qatar, Oman, Syria, Azerbaijan, Jordan, Yemen, Lebanon, Palestine, Kuwait, Bahrain, Georgia and Armenia. Some countries such as Turkey, Armenia and Azerbaijan identify both as part of Europe and the Middle East.