Districts with sprawling buildings, storage areas, extensive car-parks, yards and access roads can be extensive. Mainly built since the beginning of the 19th century, they can include large office developments, shopping centres and open-air markets, as well as factories, mills, and industrial estates. Such sites tend to be located in and around urban areas.
In some instances factories and mills have closed down, and have either been demolished or refurbished to provide housing or recreational facilities.
The parallel roofs of Holm Foundry, Glasgow, are cheek-by-jowl with urban terraced housing. Other industrial and commercial areas are noted on historical and current OS maps, while some are more readily noted when using aerial photographs.