the process of scheduling is governed by the ancient monuments and archaeological areas act 1979, which aims "to make provision for the investigation, preservation and recording of matters of archaeological or historical interest". the term "scheduled monument" can apply to the whole range of archaeological sites which have been deliberately constructed by human activity but are not always visible above ground. they range from prehistoric standing stones and burial sites, through roman remains and medieval structures such as castles and monasteries, to later structures such as industrial sites and buildings constructed for the world wars.