Thames River, London, Great Britain Winter/Spring 1997 One of the great cities in the world and Great Britain’s largest city, London, can be seen in this north-looking view. Located on both sides of the Thames River, 40 miles (64 km) from its mouth, and covering an area of over 622 sq. miles (1611 sq. km), London is a major political, financial, commercial, industrial, cultural, and transportation center. The city is one of the world’s greatest ports exporting manufactured goods and importing petroleum, tea, wool, raw sugar, timber, meat, and metals. Tourism is a major industry. The Thames River is the principal river of England and is 210 miles (340 km) long. The lower Thames is a tidal estuary with the difference of 23 feet (7 meters) between low and high tide at London Bridge. The lower course of the river from London to its mouth is one of the most important industrial regions of Great Britain. Numerous agricultural field patterns surround the London Metropolitan area.