Exotic Sumatra is one of the world's last frontiers - an island of lush tropical rainforests, extraordinary flora and fauna, and active volcanoes. Home to the Sumatran tiger and a host of diverse and dynamic ethnic groups, it is the third largest island in Indonesia and the fifth largest in the world. Vastly rich in natural recourses, over half of the country exports come from the riches of Sumatra: oil, natural gas, hardwoods, rubber, palm oil, coffee and sugar. The people maintain their strong cultural uniqueness while facing the future. In spite of evolution, Sumatra still maintains strong and well-established traditions that are rooted in their colourful past. For ancient civilizations surrounding the Indian Ocean Sumatra was a mysterious eastern island of riches, the gold land guarding the entrance to all wealth of Southeast Asia. Situated at the western rim of the archipelago along the Strait of Malacca, for centuries the region was the entry for marine trade through Southeast Asia, receiving merchants from China, India, the Middle East and Europe. The first wave started in the 2nd century with the Hindu-Buddhist Indian civilisation; later in the 14th century, Islam entered by peaceful means. Although its strategic location, its great rivers and its prized export supplies the basis for a succession of powerful kingdoms, the eastern marshes and western mountains provided protection for interior peoples who developed their own civilizations very little influenced by the outside world. Sumatra is a tapestry of ethnic groups mostly living in rural communities: in the north are the independent and devout Muslim people of Aceh; in the eastern highlands, the proud Christian Batak; and in the west, the business-savvy Minangkabau, a matrilineal society. The Kubu in the south live as did their nomadic stone-age ancestors with the Orang Laut ( sea people ) live aboard boats and ply the seas among the hundreds of islands off the east coast. Sumatra is a travel haven for nature-lovers, with its pristine environment, white water rafting, unspoiled beaches, elephants and orang-utan. Add the memorable sights of Danau Toba, Asia's largest lake, and infamous Krakatau volcano along with impressive architecture, graceful mosques and Stone Age cultures.