Islam (or Islam in Brazil) was born in Arabia, the region which the Arabs refer to as Jazirat al-'Arabi, "the island from the Arabs," which denotes its isolated nature, separated from Africa and Asia by sea . It is an inhospitable region marked by the presence of the desert, where water is a rare commodity.
Distinguished on the Arabian Peninsula three major blocs:
* The Hijaz mountain range that stretches along the Red Sea;
* The Nadj, central plateau covered with dunes;
* The South, a region known as the "Happy Arabia", which received the rain brought by the monsoons. It is the land of incense, where they lived, sedentary populations.
Source : http://pt.wikipedia.org/wiki/Hist%C3%B3ria_do_Isl%C3%A3o