Reasons for Designation
Slight univallate hillforts are defined as enclosures of various shapes, generally between 1ha and 10ha in size, situated on or close to hilltops and defined by a single line of earthworks, the scale of which is relatively small. They date to between the Late Bronze Age and Early Iron Age (eighth - fifth centuries BC), the majority being used for 150 to 200 years prior to their abandonment or reconstruction. Slight univallate hillforts have generally been interpreted as stock enclosures, redistribution centres, places of refuge and permanent settlements. The earthworks generally include a rampart, narrow level berm, external ditch and counterscarp bank, while access to the interior is usually provided by two entrances comprising either simple gaps in the earthwork or an inturned rampart. Postholes revealed by excavation indicate the occasional presence of portal gateways while more elaborate features like overlapping ramparts and outworks are limited to only a few examples. 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. Slight univallate hillforts are rare with around 150 examples recorded nationally. Although on a national scale the number is low, in neighbouring Devon they comprise one of the major classes of hillfort. In other areas where the distribution is relatively dense, for example, Wessex, Sussex, the Cotswolds and the Chilterns, hillforts belonging to a number of different classes occur within the same region. Examples are also recorded in eastern England, the Welsh Marches, central and southern England. They are a rare class of hillfort and are important for understanding the transition between Bronze Age and Iron Age communities. Bowl barrows, the most numerous form of round barrow, are funerary monuments dating from the Late Neolithic period to the Late Bronze Age, with most examples belonging to the period 2400-1500 BC. They were constructed as earthen or rubble mounds, sometimes ditched, which covered single or multiple burials. They occur either in isolation or grouped as cemeteries and often acted as a focus for burials in later periods. Where large scale investigation has been undertaken around barrows, contemporary or later "flat" burials may surround the barrow mounds in urnfields. Often superficially similar, although differing widely in size, bowl barrows exhibit regional variations in form and a diversity of burial practices. Often occupying prominent locations, they are a major historic element in the modern landscape and their considerable variation of form and longevity as a monument type provide important information on the diversity of beliefs and social organisations amongst early prehistoric communities. They are particularly representative of their period. Strip fields are characteristic of the medieval period as long thin rectangular and often sinuous fields defined by low banks or lynchets which hug hillsides and are often filled with distinctive ridge and furrow. The multi-period archaeological landscape centred on and including a slight univallate hillfort called Chalbury, two bowl barrows, part of a Bronze Age urnfield and a series of medieval strip fields survives well and in the case of the urnfield is one of the type sites for Deverel-Rimbury pottery. The landscape will contain archaeological and environmental evidence relating to the construction and development of the various features, their inter-relationships and relative chronologies, strategic and territorial significance, funerary and ritual significance, trade, agricultural practices and changes through time to technology and land use, domestic arrangements within the hillfort and the overall landscape context of all the features through time.
The monument includes a multi-period archaeological landscape situated across a prominent ridge called Rimbury, with a northern spur called Green Hill and a south eastern one called the Downs and includes the dry Coombe Valley. The landscape includes a central slight univallate hillfort which contains two bowl barrows; part of a Bronze Age urnfield to the south east; and an extensive series of medieval strip fields to the surrounding the hillfort. The hillfort surrounds the domed crest of a rocky knoll formed partly from Lower Purbeck Limestone and Portland Sands. It occupies a strategic position commanding the north end of the Rimbury ridge which splits a valley leading to Weymouth Bay. The hillfort survives as a roughly D-shaped enclosure defined by a single rampart and outer rock-cut ditch with a counterscarp bank and further internal quarry pits augmenting the rampart. It covers an area of approximately 4.5ha. There is a single gap entrance to the south east. The interior is marked by numerous circular depressions and least 30 platforms ranged around the perimeter, one of which has a defining outer bank. The depressions could be quarries of any date, but at least 20 probably represent contemporary storage pits. Limited excavations by Whitley in 1939 examined the rampart, ditch, internal quarry ditch, occupation layers including some post holes, a hut and a single storage pit. Finds included an iron knife, bone gouges, a blue glass bead, a fragmentary bronze ring, a bracelet, a piece of saddle quern, charred wheat, a spindle whorl, human and animal bones and sling-stones. There were also eleven worked flints including an end scraper and borer stratified with Iron Age material. A thin scatter of Romano-British pottery and a fragment of Samian Ware indicated later use. Within the hillfort are two bowl barrows which survive as circular mounds of between 18.5 and 20m in diameter standing to 1.7m high. The surrounding quarry ditches, from which the construction material was derived, are preserved as buried features. One was excavated by Warne in the 19th century and produced two cremation burials in fragmentary urns. To the south east of the hillfort are the buried remains of part of the 'Rimbury Urnfield' discovered and partially excavated By Hall and Medhurst during the 19th century. Over 100 urns were discovered, many fragmentary, which contained ashes and calcined bones. The majority were mouth upwards and covered with a thin flat stone. Cists were interspersed between the urns, only one contained part of a skeleton and a small urn with ashes. However, many unburnt skeletons were found beneath the urns. During extension works to the reservoir in 1979 more human bone fragments and Beaker pottery were recovered. The burial had been laid in a shallow rectangular pit with two beakers and an awl. The urnfield and bowl barrows probably once formed part of a far larger burial complex. Surrounding the hillfort and in places crossing over the ramparts are an extensive series of curving medieval strip lynchets defining narrow sinuous fields which are particularly prominent on Green Hill, on both sides of the Coombe valley and on the lower eastern slopes of Chalbury Hill. There are also several extensive quarry workings across the hillside.
PastScape Monument No:-452691, 452700, 452725 and 452694