Large univallate hillfort on Cadbury Hill


Heritage Category:
Scheduled Monument
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Date first listed:
Date of most recent amendment:


Ordnance survey map of Large univallate hillfort on Cadbury Hill
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The building or site itself may lie within the boundary of more than one authority.

North Somerset (Unitary Authority)
North Somerset (Unitary Authority)
National Grid Reference:
ST 44153 64950

Reasons for Designation

Large univallate hillforts are defined as fortified enclosures of varying shape, ranging in size between 1ha and 10ha, located on hilltops and surrounded by a single boundary comprising earthworks of massive proportions. They date to the Iron Age period, most having been constructed and used between the fourth century BC and the first century AD, although evidence for earlier use is present at most sites. The size of the earthworks reflects the ability of certain social groups to mobilise the labour necessary for works on such a monumental scale, and their function may have had as much to do with display as defence. Large univallate hillforts are also seen as centres of redistribution, both for subsistence products and items produced by craftsmen. The ramparts are of massive proportions except in locations where steepness of slope precludes easy access. They can vary between 6m and 20m wide and may survive to a height of 6m. The ditches can measure between 6m and 13m wide and between 3m and 5m deep. Access to the interior is generally provided by one or two entrances which often take the form of long passages formed by inturned ramparts and originally closed by a gate located towards the inner end of the passageway. The entrance may be flanked by guardrooms and/or accompanied by outworks. Internal features included timber or stone round houses; large storage pits and hearths; scattered postholes, stakeholes and gullies; and square or rectangular buildings supported by four to six posts, often represented by postholes, and interpreted as raised granaries. Large univallate hillforts are rare with between 50 and 100 examples recorded nationally. Most are located within southern England where they occur on the chalklands of Wessex, Sussex and Kent. The western edge of the distribution is marked by scattered examples in north Somerset and east Devon, while further examples occur in central and western England and outliers further north. Within this distribution considerable regional variation is apparent, both in their size, rampart structure and the presence or absence of individual components. In view of the rarity of large univallate hillforts and their importance in understanding the organisation and regional structure of Iron Age society, all examples with surviving archaeological remains are believed to be of national importance.

The large univallate hillfort on Cadbury Hill survives well and is known from previous excavation to contain archaeological and environmental information relating to the monument and the landscape in which it was constructed and later re-used. This is one of a number of well preserved hillforts surviving locally. Together, these will provide an insight into the Iron Age communities of the area, their economy and the political and social structure of which they were a part.


The monument includes a large univallate hillfort situated on the spur of Cadbury Hill, a carboniferous limestone ridge orientated from north-east to south-west, overlooking the valley of the Congresbury Yeo to the south and an extensive area of Levels to the west and north. The hillfort, known as Cadbury-Congresbury, has a sloping sub-rectangular interior with maximum dimensions of 340m east-west by 125m north-south, narrowing to 68m from north-south in the centre. The eastern end of the fort is c.40m higher than the western end. A number of hut circles in the western half of the hillfort's interior have been recorded by antiquarians. Surrounding the interior is a system of ramparts which vary in size and complexity according to the nature of the associated topography. The northern, southern and western peripheries of the hillfort are bounded by steep slopes which provide a good natural defence; here the monument is defined by a single stone-built rampart comprising a bank 10m wide and 1m high which on the southern side is bounded by an external terrace 15m wide. On the northern side there are known to be traces of an internal ditch which would have provided additional stone for the bank. The total width of the rampart in these areas of the monument is 25m. On the south-west side the slopes encircling the periphery of the hillfort are less steep and an additional internal rampart was constructed to enhance the defences in this area. This rampart included a bank which survives to a width of 10m and is c.0.5m high. The north-eastern area of the hilltop was its most vulnerable, as land beyond the monument is almost level with its interior. In order to compensate for this, the defences in this area were developed into a more sophisticated multivallate system. The resulting earthworks included three banks 10m-15m wide and c.1.5m high, each of which was bounded by an external ditch 10m wide. The banks stand up to 3m above the bases of their associated ditches and the ramparts have a total width of 62.5m. There is a possible entrance to the interior of the monument at this eastern end. Partial excavation of the monument in 1959 and 1970 has confirmed an Iron Age date for the hillfort. Hut circles, post holes, large quantities of Iron Age pottery and 830 sling-stones were recorded from within the interior of the monument. The excavations also demonstrated that the hilltop was occupied before and after the Iron Age. The earliest evidence for human activity on the hilltop includes a quantity of Neolithic flintwork comprising blades and waste flakes, as well as two barbed and tanged arrowheads dating from the Bronze Age. Occupation of the hilltop can also be attested during the later Romano- British period, as two hearths and an associated rectangular building which were discovered within the interior have been dated to between AD 430-450. Later, the hilltop appears to have become re-fortified, as between AD 450-480 a stone based timber-framed rampart was constructed over the area occupied during the late Romano-British period. These later defences, which are orientated north-south within the area of the Iron Age hillfort, fell out of use by the sixth century AD. A further phase of occupation then developed over the area of these ramparts. This late occupation included eight huts, two of which were circular with diameters of 15m, as well as a rectangular structure with dimensions of 8m by 3m. Finds from this period were recovered during the excavations. These included Romano-British pottery, Roman and post-Roman beads, glass, bricks, bronze and iron objects including four penannular brooches, as well as local, Gaulish and Mediterranean pottery dating to the fifth and sixth centuries AD. Some of the pottery recovered from the site had been inscribed with symbols and it has been suggested that the later settlement may have been associated with a pagan or early Christian shrine. Excluded from the scheduling are all fence posts and notice boards although the ground beneath all these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 5 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


The contents of this record have been generated from a legacy data system.

Legacy System number:
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Books and journals
Alcock, L, Arthur`s Britain, (1971), 219
Lay, S E, A Parish survey of Congresbury, (1978), 2
Lay, S E, A Parish survey of Congresbury, (1978), 2
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 52
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 51
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 51
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 51-2
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 51-2
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 51
Fowler, P J, Gardner, K S, Rahtz, P A, 'Proc Som Arch Nat Hist Soc' in Excavations at Cadbury-Congresbury, Somerset, 1971, , Vol. 115, (1971), 51
Rahtz, P A, Watts, L, 'The End of Roman Britain' in The End of Roman Britain, , Vol. 71, (1979), 196-9
Details of finds from the site,
Reference to hut circles in west,
Reference to name Cadcong,
Reference to Roman structures,


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

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