Ordnance Survey maps are among the most important historical records ever produced for Britain. They are not just maps of roads, towns and fields. They are detailed snapshots of the landscape at different moments in time, showing farms, lanes, footpaths, parish boundaries, old place-names, earthworks, quarries, mills, churches, chapels, moats, commons, woods, railways, canals and long-lost buildings.
For family historians, local historians, archaeologists, placename researchers, metal detectorists and landscape historians, old Ordnance Survey maps can help answer one of the most important questions of all: what was here before?
The Ordnance Survey grew out of the need to map Britain accurately for military and national purposes. The first official one-inch Ordnance Survey map was published in 1801, and the early mapping programme developed into what became known as the Old Series. These early maps were produced at a scale of one inch to one mile and gradually covered England and Wales.
Over the nineteenth century, Ordnance Survey mapping became more detailed and more systematic. The early one-inch maps gave a broad picture of the country, while later large-scale mapping, especially the six-inch and twenty-five-inch County Series, recorded the landscape in much greater detail. These maps are now invaluable historical documents.
The Old Series maps were the earliest national one-inch Ordnance Survey maps. At one inch to the mile, they are excellent for understanding the wider historic landscape. They show towns, villages, roads, rivers, hills, commons, woodland, parkland and the general pattern of settlement before later industrial and urban expansion.
Because they often preserve an early nineteenth-century view of the countryside, Old Series maps are especially useful for identifying older routeways, settlement patterns, historic estates, ancient parish landscapes and areas where later development has hidden earlier features.
Later one-inch maps updated and improved the national coverage. These maps are useful for seeing how the landscape changed during the nineteenth century, particularly with the arrival of railways, new roads, expanding towns, industrial sites and changing administrative boundaries.
Compared with the Old Series, these later one-inch maps are often clearer, more standardised and better suited for comparing broad landscape change over time.
The six-inch maps, at a scale of six inches to one mile, are among the most useful historic maps for local research. They show far more detail than the one-inch maps, including individual buildings, field boundaries, tracks, wells, springs, small woods, industrial features, archaeological remains and minor place-names.
For many researchers, the six-inch maps offer the best balance between detail and coverage. They are detailed enough to locate individual farms, hamlets, lanes and landscape features, while still covering wide areas.
The twenty-five-inch maps, roughly 1:2,500 scale, are even more detailed. They can show individual buildings, yards, garden plots, field boundaries, footpaths, wells, pumps, boundary stones, small industrial sites and other features that may not appear clearly on smaller-scale maps.
These maps are particularly valuable for house history, village studies, estate research, urban development, archaeological site location and detailed family history work.
In some towns and cities, Ordnance Survey produced very large-scale town plans. These can show streets, courts, alleys, individual buildings, public houses, schools, churches, chapels, factories, yards and public buildings in exceptional detail.
For urban family history, these maps can be extremely powerful. They can help identify exactly where an ancestor lived, worked, worshipped or went to school.
Twentieth-century Ordnance Survey maps record the modernisation of Britain: suburban growth, new roads, wartime and post-war development, changing field systems, lost railways, reservoirs, airfields, industrial estates and expanding towns.
By comparing nineteenth-century and twentieth-century OS maps, researchers can see how places changed across generations.
| Map Series | Typical Scale | Best For |
|---|---|---|
| Old Series | One inch to one mile | Early landscape, old roads, settlement patterns, broad historical context |
| New / Revised New Series | One inch to one mile | Later nineteenth-century change, railways, towns, roads and regional study |
| Six-Inch County Series | Six inches to one mile | Villages, farms, field systems, archaeology, placenames and local history |
| Twenty-Five-Inch County Series | Approx. 1:2,500 | Individual buildings, house history, detailed site research and field boundaries |
| Town Plans | Large-scale urban mapping | Streets, courts, buildings, factories, churches, chapels and urban ancestry |
Old Ordnance Survey maps can transform family history research. Census records, parish registers and certificates often give a place-name, street, farm or village, but a map shows the actual setting of that place.
Using old OS maps, family historians can often locate:
This helps turn a name in a record into a real place in the landscape.
Ordnance Survey maps preserve thousands of historic place-names, many of which have disappeared from modern maps. Field names, farm names, woods, lanes, hills, springs, commons and minor settlements can all provide clues to earlier land use, ownership, folklore, language and settlement history.
Placenames may hint at ancient woodland, former wetlands, old roads, religious sites, defensive sites, industrial activity or long-lost settlements. For anyone studying local history, archaeology or genealogy, these names can be extremely important.
Old OS maps are essential tools for archaeological research. They can show earthworks, tumuli, camps, moats, Roman roads, old quarries, ancient boundaries, deserted settlements, ridge and furrow, old tracks and other features that may have been damaged, ploughed out or hidden by later development.
By comparing old maps with modern aerial photography, LiDAR, satellite imagery and archaeological records, researchers can identify areas with strong potential for undiscovered sites.
For responsible metal detectorists, historic OS maps are extremely useful because they help identify places where people lived, worked, travelled, gathered and traded in the past.
Old maps can help highlight:
These locations can indicate areas of historic activity. Detectorists should always obtain the landowner’s permission and follow the law, including the Treasure Act and the Portable Antiquities Scheme guidance.
Old Ordnance Survey maps are also valuable for environmental research. They show former woodland, marshland, commons, ponds, streams, field systems, hedgerows, quarries and old industrial sites. This makes them useful for understanding habitat loss, landscape change, historic watercourses and the development of towns and countryside.
ARCHI brings together historic mapping, archaeological data and landscape interpretation to help users explore the past more effectively. ARCHI’s old Ordnance Survey map pages are designed to help researchers understand each sheet and interpret what the map may reveal.
Each analysed sheet can contain valuable information for archaeologists, landscape historians, heritage hunters, genealogists, local historians and metal detectorists alike. By combining old maps with archaeological site data and modern mapping tools, ARCHI helps users move from simply looking at a map to actively interpreting the historic landscape.
With old Ordnance Survey maps, you may be able to discover:
Ordnance Survey maps are far more than old paper maps. They are detailed historical records of Britain’s changing landscape. Whether you are tracing your family tree, studying placenames, searching for archaeological clues, researching a village, planning responsible metal detecting or exploring local history, old OS maps can reveal details that modern maps often miss.
Used carefully, they can help bring the past back into view.