 This gave them a very wide turning circle, the legacy of which are the broad, pleasant boulevards of cities such as Bulawayo, Zimbabwe, which are wide, and Grahamstown, South Africa, which are "wide enough to turn an ox-wagon".The wagon itself is made of various kinds of wood, with the rims of the wheels being covered with tyres of iron, and since the middle of the 19th century the axles have also been made of iron.The back wheels are usually substantially larger than the front ones and rigidly connected to the tray of the vehicle.