Aceh (; [ʔaˈtɕɛh]); (Jawi : اچيه); Atjeh (Dutch); or Acheh is a special region of Indonesia. The territory is located at the northern end of Sumatra. Its capital is Banda Aceh. It is close to the Andaman and Nicobar Islands of India and separated from them by the Andaman Sea.
There are 10 indigenous ethnic groups in this region, the largest being the Acehnese people, accounting for approximately 80 to 90% of the region's population.
Aceh is thought to have been the place where the spread of Islam in Indonesia began, and was a key factor of the spread of Islam in Southeast Asia. Islam reached Aceh (Kingdoms of Fansur and Lamuri) around 1250 AD. In the early seventeenth century the Sultanate of Aceh was the most wealthy, powerful and cultivated state in the Malacca Straits region. Aceh has a history of political independence and resistance to control by outsiders, including the former Dutch colonists and the Indonesian government.
Aceh has substantial natural resources, including oil and natural gas; some estimates put Aceh gas reserves as being the largest in the world. Relative to most of Indonesia, it is a religiously conservative area. It has the highest proportion of Muslims in Indonesia, who mostly live according to Sharia customs and laws.