The Annapurna trek passes through country inhabited by a wide diversity of peoples. Often you recognize on the architecture of the village, that you entered a settlement of other tribe. At the lower elevations are the tribes of the Indo-Aryan origin prevalent, e.g. Nawars from the Kathmandu Valley or Thakalis. The higher elevations are predominantly the home of the people of the Tibeto-Burmese origin, e.g. Manangpas, Gurungs and Magars. The subtropical valleys and the plains like Terai are considered the "rice bowl" of Nepal. The higher the elevation the more difficult are the conditions for the agriculture. Above 4000 m only livestock breeding is possible. Many tribes in the Himalaya played once an important part in the trading between the subcontinent and Tibet and China. Due the progress of the transportation means, the old trading route through Himalaya lost its importance. Fortunately since 1950s the decreasing incomes from trading were substituted by the rising incomes from tourism. Some tribes benefited disproportionate from the tourism, e.g. Sherpas, which populate the areas around Mt.Everest and which cornered the mounteeniring market. On the contrary stayed the people in west Nepal very poor. The west part of Nepal is lacking of huge mountains, which attracts millions of tourist to the east part of the country. For a long time the money earned by the famous Gurkha soldiers was a major source of foreign exchange in Nepal. After the Sugauli treaty was signed in 1816, the Gurkhas became a regular part of the British army. They are known for being tough, spirited and loyal, with battle skills, that have won them a place among the world's fighting elite. Contrary to some misconceptions, Gurkhas are not an ethnic group. They are fighting force that originated in Gorkha, a part of Nepal, and are made up mainly of Gurung and Magar people.