The document discusses the characteristics of central business districts (CBDs) and inner cities. CBDs typically have tall buildings, shops, entertainment venues, public transportation, and historic structures. Inner cities developed in the 19th century to house industrial workers and are characterized by high-density terraced housing, factories, canals, railways, and roads. Problems that arose in inner cities since the 1950s include industrial decline, unemployment, abandoned buildings, crime, poor housing quality, lack of open space and parking.