Thailand is an independent country that lies in the heart of Southeast Asia. The country is a kingdom, a constitutional. Thailand is the world’s 50th largest country in terms of total, with a surface area of approximately 513,000 sq km (198,000 sq mi), and the 21st most-populous country, with approximately 64 million people. The largest city in Thailand is Bangkok, the capital, which is also the country’s center of political, commercial, industrial and cultural activities. City population: 9,100,000, Metro: 11,971,000 (January 2010).