Sheffield is a big city in a region called South Yorkshire in the North of England. 534,500 people live there. Sheffield is in the middle of lots of hills. The city centre is where the River Sheaf meets the River Don, and Sheffield gets its name from the River Sheaf. The city is east of the Peak District National Park. It is estimated that Sheffield has over two million trees, which is more than any city in Europe per each person. 61% of the city is green space, such as parks and forests.