archaeological & built heritage assessment - The Heritage Council

was c. 24m, the ramparts were of dump construction, surviving to a maximum height of about 1.5m. The
palisade trench contained the burnt remains of oak timbers which provided a radiocarbon determination
of 390-370 BC (Waddell 1998).
The early medieval period (AD 400 – 1169)
The early medieval period (AD 400 – 1169) was a time of profound internal social and economic change
in Ireland. The dominant site types associated with this period include ringforts, souterrains and
enclosures. (Generally enclosures are likely to be ringforts but insufficient evidence survives to classify
them as such without recourse to archaeological excavation.) There are a large number of recorded early
medieval period sites within the waterways corridor itself, and in the wider environs.
Ringforts are undoubtedly the most widespread and characteristic archaeological field monument in the
Irish countryside. They are usually known by the names ráth or lios, forming some of the most common
place-name elements in the countryside. The ringfort is basically a circular or roughly circular area
enclosed by an earthen bank formed of material thrown up from a concentric fosse (or ditch) on its
outside. Archaeological excavation has shown that the majority of ringforts were enclosed farmsteads,
built in the early medieval period (AD 500 – 1169). Though not forts in the military sense, the earthworks
acted as a defence against natural predators like wolves, as well as against the cattle raids that were a
characteristic of that period. Souterrains (underground chambers) are often found in association with
ringforts. In total, there are one hundred and nineteen ringforts, nine cashels, sixty-three enclosures and
two souterrains recorded from the study area in counties Roscommon and Leitrim, an indication of
intensive early medieval settlement adjacent to the waterways corridor.
There are some sites that are only known from the OS 6-inch maps where they are usually marked as
enclosures. Although many have now been removed by land reclamation projects, most were probably
ringforts or cashels, but in the absence of morphologically diagnostic features they can only be classified as
'Earthworks'. Also there are some anomalous monuments, which because of their condition cannot be
described as anything other than earthworks. Generally it is accepted that these monuments are dated to
the early medieval period and there are thirty-seven such examples recorded from the study area.
Crannógs are related to ringforts, but have been specially adapted to a watery environment, that is, they
were lake-dwellings. Some have been located on natural islands; however they were often constructed on
entirely artificial foundations, largely retained by a ring of closely set vertical piles, which form a palisade
around the site. Lakes can provide added security to those under threat, but this aspect does not seem to
have been exploited until the first millennium AD by the construction of crannógs. Artificially constructed
crannógs in deep water were settlement sites of a particularly defensive character. Surrounded by water,
access could only be achieved by boat, probably to a rudimentary pier, although the stone piers visible at
many of the crannógs are probably modern conveniences (Moore 2003). Crannógs can be eroded by
currents in the lakes or by human interference, especially in drainage or navigation works, and many
crannógs were discovered, and interest in them stimulated, by drainage works in the late nineteenth
century (Wood-Martin 1886). There are twenty-five crannógs in total recorded from the lakes of the
study area. There are also six dug-out canoes retrieved from the study area at Attirory (NMI Record
Only), Corry, Lough Allen (NMI ?), Drumsna (NMI 1935), Kilmore (NMI ?) and Lough Allen (NMI
IA/92/59), In addition, several other artefacts have been discovered from crannóg contexts including a
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