Conurbation

As neighbouring towns and cities spread outwards, their built-up areas may join to form a conurbation. A very large urban population can therefore extend across several connected settlements rather than fitting within one city's administrative boundary.

Several of these concentrations are conurbations. As neighbouring settlements grew outwards, their built-up areas joined together. Important examples include Greater Manchester in the North West, the West Midlands centred on Birmingham, West Yorkshire centred on Leeds and Bradford, and Tyneside centred on Newcastle in the North East.

Around Mumbai it is difficult to identify a single, neat boundary because urban expansion has absorbed and linked neighbouring settlements into a large conurbation. Rural land can remain where conditions make building difficult. The fringe should therefore be understood as an uneven transition, rather than a perfect outer ring.

As neighbouring settlements expand and join, they can form a conurbation.