Indonesia is the biggest archipelago in the world, 17,504 large and small tropical islands, white sandy beaches of which many are still uninhabited and even unnamed. To give you an idea about its scale, it is as wide as the United States from San Francisco to New York, equaling the distance between London and Moscow. Indonesia encompasses population of 215 million people from more than 200 ethnic groups and its national language is Bahasa. 
To read historical, ethnic and geographical information from 2011 WORLD BOOK, click here.