Yes, you heard that right. What you think of London is actually just a small urban area part of the Greater London region. The city of London covers only 1.2 square miles and has a population of around 7,500 residents. As such, the city of London is actually the smallest city in England. Greater London, on the other hand, is an English region, which encompasses surrounding towns covering 606 square miles and having a population of over 8.7 million residents.