Noisy, vibrant and truly multicultural, London is a megalopolis of people, ideas and frenetic energy. The capital and largest city of the United Kingdom, it is also the largest city in Western Europe and the European Union. Situated on the River Thames in South-East England, Greater London has an official population of a little over 8 million, but the estimate of between 12 and 14 million people in the greater metropolitan area better reflects its size and importance. Considered one of the world's leading "global cities", London remains an international capital of culture, music, education, fashion, politics, finance and trade.
Original article source: Wikivoyage, where you find useful information about London. Creative common licence