This list of the tallest buildings and structures in the Birmingham Metropolitan Area, West Midlands ranks buildings and free-standing structures by height, based on standard height measurements that include spires and architectural details but exclude extraneous elements added after completion of the building. The tallest building in the metropolitan area is The Mercian, a residential tower located in Birmingham's Westside district. The tallest structure, also in Birmingham, is the 140-metre (458 ft) BT Tower. Both are set to be surpassed by Octagon, a skyscraper currently under construction in Birmingham City Centre. Birmingham Metropolitan Area The Birmingham metropolitan area is an urban agglomeration located in the West Midlands region of England with a population of around 4.3 million people, making it the second largest metropolitan area in the United Kingdom. It comprises the three cities (Birmingham, Coventry, Wolverhampton) and four metropolitan boroughs (Dudley, Sandwell, Solihull, Walsall) which make up the Metropolitan county of the West Midlands, along with its commuter zones, which extend into the neighbouring district authorities of Bromsgrove and Redditch in Worcestershire; Cannock Chase, Lichfield, South Staffordshire and Tamworth in Staffordshire; and all five district authorities of Warwickshire, including the towns of Bedworth, Coleshill, Nuneaton, Royal Leamington Spa, and Warwick itself. Each of these authorities has at least one high-rise, or tall building or structure ≥35 metres in height. A number of sizeable settlements fall outside the morphological boundaries of the Birmingham Metropolitan Area but still form part of its economic and infrastructural hinterland. Amongst these, the cathedral city of Lichfield, the towns of Cannock, Hednesford and Rugeley in Staffordshire, Rugby and Stratford-upon-Avon in Warwickshire, and Kidderminster in the Wyre Forest District of Worcestershire. For completeness, the tall buildings and structures in these places are included in the listings below but, for accuracy, are not designated a metropolitan area ranking. Like other regional conurbations in the United Kingdom, the Birmingham Metropolitan Area is polycentric, with several primary urban areas and satellite towns overlaying traditional market towns and civil parishes, separated by areas of protected green space. This is reflected in a diverse urban landscape characterised by examples of Medieval, Tudor, Jacobean, English Baroque, Georgian, Victorian, Edwardian, Modern, Postmodern and Contemporary architecture. Each of these architectural periods is represented by at least one tall building or structure. All of the listings on this page are colour coded according to the authority in which they are located, based on the map