‘Fogou’ is a Cornish word meaning a cave, and Cornish fogous are
prehistoric underground passages constructed by excavating a trench
and lining its sides with either large stone blocks or drystone
walling, and then roofing it over with large flat slabs. Halliggye is
a good example of a large well preserved Cornish fogou.
There are twelve surviving fogous in Cornwall, but many more may
have been ‘lost’ over the centuries and new examples are revealed
from time to time. They were constructed from the 5th Century BC to
the first two centuries AD, placing them in the late Iron Age and
early Roman periods. Their function remains a mystery; the most
plausible explanations see them as places for storage, or for
refuge, or as the setting for religious or ritual activities.
Similar sites are also found in Brittany, Ireland and Scotland where
they are known as souterrains, but their architecture, date range,
and possibly also their function(s), differ from the Cornish sites.
In Ireland, for example they may be constructed or continue in use
into the mediæval period.
The majority of fogous are associated with contemporary settlements
and Halliggye is no exception, being situated within the earthworks
of an Iron Age farming hamlet or Round. The two concentric ramparts
of the round survive best in their north-eastern quadrant and
contain a broad curving ditch. The modern hamlet is largely confined
within the area of the round and the fogou is situated in its
The modern entrance was constructed during repair work carried out
in 1980; a modern flight of stone steps leads down into the original
20m long sloping passage orientated north-west to south-east which
ends in a small ‘creep’ of reduced height, divided into two parts by
a doorway framed by massive stone slabs. This section originally
ended in a doorway, now blocked off, which opened into the ditch,
and thus provided an alternative entrance/exit to the round. Towards
the far end of this straight passage a long curving side passage
runs westwards for 28m towards a short south facing creep which ends
in bedrock. An ‘old’ entrance is visible in the south wall of this
curving passage about halfway along its length. Both passages are
over 2m high in places. Precise dating of the fogou is difficult,
but the evidence from pottery found during the excavations, which
included local Iron Age cordoned wares and some sherds of Samian
ware from southern Gaul, suggest a continuity of use from the 4th
Century BC to at least the 2nd Century AD.
The fogou and the round within which it sits lies on the western
slopes of a hill with panoramic views over the Helford river and
beyond - a landscape rich in settlements broadly contemporary with
the Iron Age and Roman occupation at Halliggye. These include other
round sites which share similar hillside locations, and the very
large hillfort known as Gear Camp which is sited just 1km to the
The modern-day settlement and manor of Halliggye is first recorded
in the Domesday Book of 1086 where it is spelt 'Heligin'. The name
is Cornish and means 'Place of Willow Trees'. The Vyvyan family
settled at Halliggye in 1427 and in 1861 Sir Richard Rawlinson Vyvyan
published a comprehensive account for the Journal of the Royal
Institute of Cornwall on restoration work carried out on the fogou.
During World War II the fogou was used as an ammunition store by
the Manaccan Auxiliary Unit.
The fogou is also of special importance as a winter hibernation site
for Horseshoe bats, a protected species. Access to the fogou is
therefore only possible between April and September.
The site lies within the Trelowarren Estate and a small entrance fee
is levied. Access is via a short walk from the main car park or from
a lay-by which has been constructed on the estate road which runs to
the north of the fogou.
Clarke, EV, 1961. Cornish Fogous.
Cooke, IM, 1993. Mother and Sun. Over Wallop, BAS Printers Ltd.
Johns, C, 2005. Halligye Fogou, Mawgan-in-Meneage, Cornwall.
Historic Environment Service, Cornwall County Council.
Startin, W, 1981. Halligey Fogou, Trelowarren in Cornish
Archaeology 20, pp219-220.