Grand Erg Oriental follow the wind's direction. There are other types of dunes, as well as "complex" dunes. Saharan winds are also known to clear an area of sand altogether, leaving bare rock (hamada) or gravel (reg). The "Grand Erg Oriental" is accessible overland by an Algerian road, which goes south from Constantine. It passes through the Aurès mountains, then salt lakes by the city of Biskra. Next the road skirts the western edge of the erg. After about 500 km. in all, it reaches the ancient oasis of Ourgla [Wargla]. Since late antiquity Wargla was a stop for the Saharan trade, being
Varieties of Arabic French in Lebanon, and English and Hebrew in Israel. However, a much more significant factor for all five dialect groups is, as Latin among Romance languages, retention (or change of meaning) of the form of Classical Arabic used in the Quran. The following example illustrates similarities and differences between the literary, standardized varieties, and major urban dialects of Arabic. Maltese, a distantly related Siculo-Arabic language descended from Maghrebi Arabic is also provided. "True pronunciations differ; transliterations used approach an approximate demonstration. Also, the pronunciation of Modern Standard Arabic differs significantly from region to region." For the sake of comparison, consider