Heritage of Wales

Aerial Photography Gallery – Wales from the Air

Aerial photography is one of the most powerful ways to document the changes in the landscape of Wales from earliest times to the modern day. From high above archaeologists can look down on centuries of landscape change, photographing known monuments, discovering long-hidden sites, and providing a new perspective on our cities, towns and built heritage.

The Royal Commission’s aerial photograph archive illustrates the breadth of Welsh culture and landscape, from prehistoric tombs, Iron Age hillforts, Roman towns and medieval castles to country houses, historic docks, wartime defences, and modern architecture. More general views of the Welsh landscape are also available, whether you are looking for limestone coastal scenery, a beach in summer, the Millennium Stadium or the summit of Snowdon. At the National Monuments Record of Wales ‘oblique’ aerial photographs (looking out from a light aircraft) taken by the Royal Commission since 1986 form part of a wider archive of historic (post-1940) oblique and ‘vertical’ photographs (looking straight down from a survey aircraft), showing the changing face of Wales.

This online gallery showcases some of the best aerial imagery from the Royal Commission’s oblique archive, showing not only traditional archaeological sites and landscapes but also more unusual views of Wales’ modern buildings, coastline and landscape.

Discovering the past from the air – cropmarks

  • Cropmark enclosure, Cawrence, Ceredigion. Cropmarks in a ripening summer crop show the clear outlines of the plough-levelled ditches of a pre-Roman, Iron Age defended farmstead. The outer enclosure may have been for keeping stock like sheep and cattle, whilst the inner enclosure, reached by a short, gated passageway (on the left side), was probably reserved for round houses. (Image: DI2005_0139. NPRN:308918)
  • How cropmarks form: From Iron Age farm to low earthwork and then to modern farmland. This sequence illustrates how certain elements of a prehistoric farmstead, particularly the enclosure ditch, defensive rampart and postholes, can survive as below-ground features and effect the way that an arable crop or grassland grows during a dry spring and summer. (Image:DI2006_1443)
  • Dyffryn Lane Henge, Montgomeryshire. The long summer drought of 2006 produced very clear cropmarks of this Neolithic henge (bottom right, under excavation) and plough-levelled Bronze Age barrows (circles, centre-left), near Welshpool. The way that the buried ditch of the henge shows as a dark green cropmark, and is also revealed in the excavation trench, is particularly striking. (Image:AP_2006_3363. NPRN:306967)

Each year Royal Commission archaeologists discover long-forgotten sites and monuments from the air. Countless archaeological sites have been lost to agriculture, destruction and erosion in the centuries since they were first built. At ground level nothing may remain to show us the position of prehistoric farmsteads or Roman villas, but beneath the topsoil substantial remains may still survive of buried ditches, wall footings and other features. Crops growing on well-drained lowland soils in dry summers can reveal the shapes and positions of these buried remains through cropmarks.

Cropmarks happen when plants growing over buried archaeological features, like old ditches or postholes, grow taller and greener over the more fertile, damp soil in the holes. Conversely, those growing over buried stonework and walling quickly ripen and turn yellow in response to the shallow soil and lack of nutrients. These differences in summer growth, which can appear like an X-ray of the field, are best seen from the air. In very dry summers, when conditions are exceptional, many hundreds of new cropmark sites can be discovered in the space of just a few months, showing the fundamental contribution aerial photography can make to understanding the archaeology of Wales.

Recording earthworks in low light

A great many archaeological sites in Wales survive as grass-covered ‘lumps and bumps’. Some earthworks are prominent and well preserved, like some medieval mottes (castle mounds) or Iron Age hillforts. Others are far less well preserved. Vestigial earthworks are best photographed under low, raking sunlight to reveal their patterns in light and shadow. During the summer months late evening shadows can provide ideal conditions, but vegetation can obscure some detail. During winter, especially after the first fall of snow, grass and bracken are low and many upland earthworks can be photographed with breathtaking clarity.

The outlines of very faint earthworks become much clearer from the air if photographed in sharp frost or under a light dusting of wind-blown snow. In Wales the amount of new discoveries made during earthwork recording in the hills and mountains is comparable in number to the summer discoveries of cropmarks in lower-lying areas.

  • Tyddyn Mawr coal workings. This very clear aerial photograph of an area of rural coal workings in central Anglesey was taken under a hard January frost around thirty minutes after sunrise. The workings are surrounded by relict ridge-and-furrow ploughing. (Image: DI2006_0259/NPRN 300520)
  • Gaer Fawr hillfort. A winter view of this large Iron Age hillfort in Ceredigion. Winter sunlight highlights the remains of the main, inturned gateway (centre foreground) and the broad terraced ramparts along the right-hand (north) side of the fort. (Image:DI2006_2003/ NPRN 303579 ).
  • Penally practice trenches, Pembrokeshire: a detailed view from 1995, showing the excellent state of preservation of these near-century-old earthworks and the sawtooth trench lines. Signs can also be seen of other accommodation built into the trench lines, which could include dugouts, strongholds, field hospitals and canteens. In places the Penally trenches are dug through the bedrock, which must have been exceedingly hard work. (Image:DI2006_0374/NPRN 268143 ).

Prehistoric Wales

Without the addition of aerial discoveries our understanding of the nature and extent of early settlement in Wales would be very limited. We know that Wales was intensively farmed and settled from the Neolithic, 6,000 years ago, and thousands of significant ancient monuments have been ‘rediscovered’ since the flying programme began.

  • Gop Cairn. The massive Gop Cairn near Prestatyn in north Wales commands Gop Hill and is believed to have Neolithic origins. In the foreground below the cairn can be seen the Gop Cave. (Image: DI2007_0640/NPRN 306725).
  • Castell Henllys hillfort. Castell Henllys in Pembrokeshire is an Iron Age fort where reconstructed roundhouses are based on actual excavated evidence. This view from 2003 shows the main gateway (centre-right), with its gateway passage and the positions of recessed guardrooms marked in timber. The site is fully open to the public. (Image: DI2006_1291/NPRN 94989 ).
  • Banc Du prehistoric enclosure. Occupying the summit of a low hill overlooking New Inn in Mynydd Preseli in Pembrokeshire are the remains of an early defended enclosure, first discovered from the air by the Royal Commission in 1990. The enclosure uses steep rocky slopes on the east side as a natural defence, with ramparts completing the circuit on the more level ground to the west and north. It has much in common with causewayed enclosures, a very rare type of monument built during the early Neolithic period. In 2005 a ditch section was excavated, and radiocarbon dates from middle fills of the ditch indicate it was dug by 3,000 BC, confirming late Neolithic occupation. (Image: DI2006_1299/NPRN 308024).

Roman Wales

The Royal Commission holds specialist aerial photographs of sites and landscapes from across Wales. Welsh geology, archaeology, history, industry and architecture are well recorded. Regular photography of Scheduled Ancient Monuments for Cadw also ensures that Wales’ most important heritage sites are featured in our archive.

  • Y Pigwn Roman marching camps. These two overlapping Roman marching camps command a ridge to the east of Llandovery in central Wales. They were built as temporary overnight camps for detachments of Roman troops, pushing into the hill country of central Wales on campaigns between AD 74-8. The Roman earthworks are crossed in the foreground by a line of post-medieval tilestone quarries. (Image:DI2006_0230/NPRN 92004).
  • Forden Gaer Roman fort. Cropmarks (centre-right) show the double-ditched defences and internal street pattern of this major Roman fort which survives in the Welsh borderlands near Montgomery. It commanded a bridging or fording point on the River Severn (at lower left). The fort complex is still under the plough, but summer cropmarks regularly reveal details of the surrounding network of Roman roads, military structures and contemporary rural settlement. (Image: CD2005_613_014/NPRN 94012).
  • Caerleon Amphitheatre. The striking outline of this well-preserved Roman military amphitheatre in south Wales, excavated by Mortimer Wheeler, is highlighted by low autumn sunlight. (NPRN 95650; DI2005_0468).

Medieval castles and defences

Varied examples of castles, fortified country houses and defended moated homesteads of the medieval period survive across Wales. Their strategic locations and general layout can often be shown to advantage in the aerial view.

  • Caernarfon Castle. Caernarfon retains its remarkably intact medieval town defences, complete with towers and the sites of gateways. This aerial view illustrates the strategically strong coastal position of the town and castle. (NPRN 95318; AP_2006_3497).
  • Flint Castle. A winter view of Flint Castle showing its position on the very edge of the tidal mud flats of the River Dee. Its massive circular keep (upper right) was a particularly strong feature of the castle. (NPRN 94448; DI2007_0674).
  • Talybont Castle, motte. The well-preserved motte (medieval castle mound) of this earth and timber castle sits on a ridge overlooking the M4 motorway near Pontarddulais in south Wales. The outer bailey, the enclosure where houses and workshops would have stood below the castle, has long been plough-levelled. Even so, cropmarks in this aerial photograph show the clear outline of the buried bailey ditch with the site of the main gateway on the far side. (NPRN 303962; DI2006_1779).

Medieval Wales

The surviving structures of the medieval church in Wales, as well as sites of towns and villages, form enduring sights in the landscape.