Details

The monument is situated on salt marsh adjacent to Pyefleet Channel in the
western half of Mersea Island, approximately 750m north west of Maydays
Farm. It includes the remains of a Roman salt manufacturing area (saltern)
visible as a group of earthworks clustered around a central mound. Soil
from associated buried remains exhibits a distinctive red appearance
caused by the salt manufacturing process, hence the term `red hill' used
locally to describe such sites.

The principal features of the saltern are a substantial mound surrounded by a
square bank and an earthwork causeway which runs from the bank to the modern
sea wall.

The enclosure bank survives to a height of up to 2m along parts of its
southern, eastern and western sides (the northern side having been
partially eroded by tidal action) and is 4m wide, enclosing an area of
approximately 50 sq m. On the outside of the bank is a 1m wide ditch.
Within the enclosed area, in a roughly central position, is the mound of
the red hill which survives to a maximum height of some 10m. Running in a
south easterly direction for some 70m, the southern bank of the enclosure
survives as a raised earthwork platform measuring 10m to 15m wide. This
appears to form a causeway across the salt marsh, connecting the monument
to the adjoining pasture south of the sea wall. It is an integral part of
the monument and is included in the scheduling.

The monument may belong to two periods. Excavations have shown the saltern to
be early Roman in date; whereas the banked enclosure and earthwork causeway
may be later additions, representing reuse of the raised ground of the red
hill as a dry enclosure for grazing livestock.

Investigative excavations in 1892 confirmed that the mound contained burnt
rubble, Romano-British pottery and fired clay artefacts (briquetage) used in
the salt production process. The briquetage includes pedestals and firebars
used for both supporting the pans of concentrated brine above the fire during
the evaporation process, and for supporting vessels containing the evaporated
salt in a drying chamber. Other features associated with salt making will
survive within the raised platform and mound, including the settling tanks
(large clay tanks in which the brine would have been left to evaporate
naturally prior to heating in the kiln) and parts of the kiln structures
(hearths in which the fire was lit and flues and combustion chambers for
firing up the kiln). In between these structures will lie the remains of
working platforms with their associated middens containing bone and ceramic
artefacts.

Much of the soil of the salt marsh immediately adjacent to the monument is
also red in colour: the colour resulting from the heating process used to
concentrate the brine. These areas are thought to represent further open
hearths or fire floors and are included in the scheduling.

All modern fenceposts are excluded from the scheduling, although the ground
beneath them is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.

Source: Historic England

Reasons for Scheduling

Salt has been produced from seawater, or, in inland areas, from brine springs
since Bronze Age times. Some aspects of technology employed in the Late Iron
Age and Roman periods display a continuity with earlier production methods,
however some native British innovations were introduced in the first century
BC. At coastal sites brine, from which the water was evaporated to produce the
salt, was collected in clay settling tanks filled at high tide. At inland
sites brine springs would have provided the raw material. The settled brine
would have been transferred to evaporation pans. Salt making was a summer and
autumn activity when solar evaporation of the brine would have been a
possibility even if it was not practised at all sites. Alternatively an
artificial heat source could be applied to the brine to evaporate the water to
obtain the salt crystals and then to dry them out fully ready for storage and
eventual use. Late Iron Age and Roman salterns therefore include a range of
structures connected with the collection and evaporation of brine and the
drying of salt crystals and can vary from site to site depending on the
preferred practice of the individuals operating the industry. A saltern of
Late Iron Age to Roman date might typically include a sequence of numerous
settling tanks, an evaporating hearth or enclosed kiln in between which would
be working platforms with their associated middens containing bone and ceramic
artefacts. The kiln would have a hearth and associated flues and combustion
chambers.

The seasonal nature of the industry would result in the component structures
being rebuilt at the beginning of each summer so a site may include a number
of successive kilns and open hearth structures representing occupancy of the
site over many decades. Mounds of accumulated debris would include the fired
clay artefacts used in the salt production process known as briquetage:
pedestals and firebars (used for supporting both the pans of concentrated
brine above the fire during the evaporation process and then the evaporated
salt in vessels in a drying chamber); pans and bowls containing the brine and
wedges and pinch-props (used to keep the vessels apart during the heating
process) and salt-cake moulds. In some parts of the country the soil of the
resultant mound has a distinctly red appearance (caused by the heating
process) and therefore salterns in these areas are known locally as red hills.

The appearance of a comparatively large number of salterns during the Late
Iron Age is thought to have been indicative of a significant rise in
population at that time and the development of trade. Society during the early
Roman period would have grown increasingly sophisticated and would have
demanded more salted meat and fish and along with the salt cakes themselves
these products would have been traded far and wide. Salt was also used to cure
leather and the arrival of the Roman army in Britain would have increased
demand for this use. Salt was an expensive product and this method of
producing it appears to have continued on in this way well into the medieval
period and beyond, finally declining during the 17th century with the mining
of cheaper and superior rock salt.

Once common in coastal and estuarine localities, surviving salterns are
now extremely rare and most survive only as soilmarks. In Essex, out of
over 300 salterns recorded less than ten are have survived as standing
earthworks. This example 750m north west of Maydays Farm is the best
preserved of the Romano-British monuments on this length of the coast.
Structures and artefacts preserved within the stratigraphy of the saltern
will provide valuable information about saltmaking in this area; their
study will greatly enhance our understanding of the processes involved and
the technology utilised in the production of salt during the Roman period.

Source: Historic England

Sources

Books and journals
Fawn, A J et al, The Red Hills of Essex: Salt-making in Antiquity, (1990), 73
Hull, MR, The Victoria History of the County of Essex, (1963), 157
Stopes, H, The Salting Mounds of Essex: Volume I, (1887), 103
Cole, W, 'Essex Naturalist' in Exploration of some Red Hills in Essex, , Vol. 14, (1906), 170-183
Other
Appendix 2, Heppell, E and Brown, N, Greater Thames estuary Archaeological Assessment Report, (2001)
Black and white prints, McMaster, T, Nos. 8 and 10, (1980)
Black and white prints, Strachan, D, BW/99/22/15, (1999)
Black and white prints, Strachan, D, BW/99/22/15, (1999)
Colour prints, Tyler, S, CP/00/31/14, 15, (2000)
Colour prints, Tyler, S, CP/00/32/11, 12, 13, (2000)
In Essex SMR, McMaster, I, Nos. 8 and 10, (1980)
NMP Plot 1: 10 000, Ingle, C, NMP sketch plot TM01NW, (1996)
NMP Plot 1:10 000, Ingle, C, NMP Plot TM01NW, (1996)
Tyler, S, MPP Film, (1998)
Tyler, S, MPP Film, (1998)

Source: Historic England