The north-eastern region is in part occupied from the Khorat Plateau, a series of undulations placed between 100 and 200 meters high, in this area much of the border with Laos is marked by the Mekong river, the largest river of Indochina peninsula. The center of the country is characterized by a wide valley where flows the Chao Phraya River, the most important river of Thailand, which forms a large, populated and intensely cultivated plain, in this region, near the sea, is also the capital Bangkok. The part of Thai territory that occupies the Malay peninsula is made up of narrow coastal plains and isolated peaks, the coast of the Gulf of Siam is often low and bordered from lagoons and islands (Ko Samui (228 sq km), Phangan (168 sq km) , etc..), while that of the Andaman Sea is rocky, jagged and full of islands (Phuket (543 sq km), Phi Phi Islands, Ko Lanta Yai, etc..). Thai economy is a economy in strong development, agriculture has as strength the rice cultivation practiced in the vast plain of the Chao Phraya River, regarding rice production Thailand is one of the leading world producers. Among other crops are maize, cassava, peanuts, tobacco, sorghum, beans, sweet potatoes, fruits (bananas, pineapples, citrus fruits, mangoes), cotton, sugarcane. Thailand is the first world producer of rubber, cultivated in the region of the Malay peninsula. The forest resources are rich in valuable wood, including teak, ebony, sandalwood and yang. Of great importance are fishing (herring, anchovies, mackerel) and livestock (cattle, buffaloes, pigs and poultry). The subsoil is rich in tin (one of the first world producers), tungsten, iron, lead, precious stones (sapphire), oil and natural gas. The industries are concentrated almost exclusively in the capital Bangkok, more developed areas are textile, food, chemical, petrochemical and engineering. An area of great economic importance is tourism.