Ethiopia falls into four main geographic regions from west to east—the Ethiopian Plateau, the Great Rift Valley, the Somali Plateau, and the Ogaden Plateau. The Ethiopian Plateau, which is fringed in the west by the Sudan lowlands (made up of savanna and forests), includes more than half the country. It is generally 5,000 to 6,000 ft (1,524–1,829 m) high but reaches much loftier heights, including Ras Dashen (15,158 ft/4,620 m), the highest point in Ethiopia. The plateau slopes gently from east to west and is cut by numerous deep valleys. The Blue Nile (in Ethiopia called the Abbai or Abbay) flows through the center of the plateau from its source, Lake Tana, Ethiopia's largest lake. The Great Rift Valley (which in its entirety runs from SW Asia to E central Africa) traverses the country from northeast to southwest and contains the Danakil Desert in the north and several large lakes in the south. The Somali Plateau is generally not as high as the Ethiopian Plateau, but in the Mendebo Mts. it attains heights of more than 14,000 ft (4,267 m). The Awash, Ethiopia's only navigable river, drains the central part of the plateau. The Ogaden Plateau (1,500–3,000 ft/457–914 m high) is mostly desert but includes the Webe Shebele, Genale (Jubba), and Dawa rivers.
Ethiopia's population is mainly rural, with most living in highlands above 5,900 ft (1,800 m). Almost half the people are Muslim, while over a third belong to the Ethiopian Orthodox Church; about 12% practice traditional religions. There are a great number of distinct ethnic groups in Ethiopia. The Amhara and Tigreyans, who together make up about a third of the population, live mostly in the central and N Ethiopian Plateau; they are Christian and hold most of the higher positions in the government. The Oromo, who make up about 40% of the country's people, live in S Ethiopia and are predominantly Muslim. The pastoral Somali, who are also Muslim, live in E and SE Ethiopia. Until the 1980s a small group of Jews, known as Beta Israel or Falashas, lived north of Lake Tana in Gondar. In the midst of famine and political instability, 10,000 Ethiopian Jews were airlifted (1984–85) to Israel, and another 14,000 were airlifted out in 1991. By the end of 1999 virtually all the Falashas who were practicing Jews had been flown to Israel; a number of Falash Mura, Falashas who had converted to Christianity in the 19th cent., were allowed to immigrate to Israel in the next decade.
Amharic is the country's official language, but a great many other languages are spoken, including Tigrinya, Oromo, Somali, and Arabic. A substantial number of Ethiopians speak English, which is commonly taught in school.