Scheduled ancient monument (SAM)
Ancient monuments of national importance, the preservation of which is desired, are put on a list, or schedule. From that point, permission to do anything to such sites – including geophysical work, fieldwork or excavation, as well as modern developments that might affect the archaeology – has to be obtained from the relevant department of national government – English Heritage (for England), Cadw (Wales) or Historic Scotland (Scotland), all acting for the Department of National Heritage. SAMs include bridges, ruined structures and uninhabited buildings as well as the more familiar barrows, hillforts, castles and monasteries. Inhabited structures tend to be listed buildings, but there is an overlap of both forms of statutory protection. Only a very small percentage of known sites are scheduled as monuments, although a big programme is in hand to add large numbers of other sites in the next few years.

Sections
Often a difficult concept for visitors to archaeological sites to understand. Archaeologists often cut through sites to reveal the layers (stratigraphy) under the topsoil. These 'sections' – like a layer cake with a slice removed – frequently reveal ditches and pits 'in section', which the archaeologist then refers to as if they were still open and obvious when all the visitor can see is the trench! In practice, a well-positioned section gives a detailed look at the history of a site – from the geology (or 'natural' as it tends to be called) at the bottom, up through the layers that result from construction and occupation on the site, with recutting of ditches, replacement of walls and the like, to the abandonment of the site and the formation of a soil with turf at the top. The objects, especially pottery and coins, associated with these layers in the section give good evidence of the date of occupation on the site.

Sherd
A broken piece of pottery.

Sites and Monuments Record
This is a record of all the known archaeological sites, finds, earthworks and so on. Each county has one, usually located in the Planning Department and maintained by the county archaeologist.

Snails
The shells of these can be used rather like pollen grains as evidence of land use and the landscape in the past. Snails live only in particular environments, do not travel far (or fast) and, when they die, their shells are left behind in the soil as indicators. The snail specialist can take a section through a site, look at the species present as shown by the shells, and, with the knowledge of the sort of environment they prefer, such as wet and shaded or dry grassland, make some assessment of what the countryside was like and how it has changed. This is yet another aspect of environmental archaeology.

Soil profile
Soil science is a complex subject, and the variety of soils that can be found even in such a relatively small area as the British Isles is enormous. It is useful for archaeologists to know what the 'natural' soil profile is in an area being worked so that features and layers formed as a result of human activity over long periods can be understood.

Stone Age
A catch-all phrase for the period of human prehistory characterised by the use of stone tools. In Britain, the first traces of human occupation date from about 450,000 BC and the first metalworking is found at the beginning of the Bronze Age, around 2300 BC, so the Stone Age covers a huge span of time. Archaeologists prefer the more clearly defined periods: Palaeolithic, Mesolithic, Neolithic, which are also divided up into shorter sub-periods.

Stonehenge
Probably Britain's most famous ancient monument, Stonehenge was built in various stages. The earliest, around 3000 BC consisted of a bank and external ditch with a single entrance (the classic 'henge' monument). Around 2100 BC, the 80 huge Bluestones were brought to the site from the Preseli Mountains in south-west Wales. The most famous phase of the monument's construction took place around 2000 BC, when the lintelled circle and horseshoe of sarsen (standing) stones was erected.

Stratigraphy
See sections.

Stuart England
The Stuart dynasty, which followed the Tudors, started when James VI of Scotland (the son of Mary, Queen of Scots) become James I of England from 1603-25. His son, Charles I (reigned 1625-49) was beheaded following the civil war, leading to the republican Commonwealth (1649-53) and Oliver Cromwell's rule as Lord Protector (1653-58). The monarchy, and the Stuart dynasty, was restored with Charles II (1660-85), James II (1685-88) and William III and Mary II (1688-1702). See the Channel 4 History website on Stuart England.

Surveying
Archaeologists have to ensure that they know the position of their site, excavations, trenches or areas of fieldwork in relation to the general landscape, since the actual position is itself usually of significance. Surveying can range from fairly simple jobs carried out with gridded paper (see grids), measuring tapes and canes or ranging rods to the use of theodolites, levels or modern computerised equipment such as an EDM.