Artificial boundaries and markers can last centuries, indeed millennia in the landscape. Some of the most prominent examples in Britain are late prehistoric and Roman routeways and early medieval boundaries such as Offa’s and Watt’s dykes. Even in a heavily urbanised area such as the Manchester city region the continuity of landscape boundaries, both natural and artificial, was very high. One of the longest-lived boundaries in this area is a feature known as Nico Ditch, a large earthwork lying between the River Mersey to the south and the River Medlock to the north, comprising a ditch and possibly a bank that runs for roughly 12km from Ashton Moss in Tameside in the east (SJ 920 986) to Hough Moss in Manchester in the west (SJ 828 941), and studied fitfully by scholars since the late 19th century.
The best-preserved sections, on Denton golf course and in Platt Fields are protected as scheduled ancient monuments. Although most of its length has now been built over its antiquity is indicated by the two main ways in which it dominated the landscape of the middle reaches of the Mersey Basin; firstly, for much of its length it was used as a manor or parish boundary for over 800 years (it is first recorded around 1200 in land deeds); secondly, along its entire length the field patterns to the north and south of the monument took their alignment from this landscape feature.
Since 1990 archaeologists have been attempting to establish its original function as redevelopment threats mount, and to this end sections across the course of Nico Ditch have been excavated at six locations: Audenshaw Lodge in Denton (1996), Reddish (1990), Levenshulme (1992), Platt Fields in southern Manchester (1997), Gorton in east Manchester (2008), and Longford Park (2015). The latest section to be threatened is the western end through Ryebanks Fields on the Chorlton/Stretford border and close to where research test pitting for the Dig Greater Manchester project looked at the line in Longford in 2015.
The best preserved of these sections is the earthwork investigated at Platt Fields in Manchester early in 1997, which has none of the massive later reworking and drain intrusions within the ditch seen at the excavations in Audenshaw Lodge, Gorton, Levenshulme and Reddish. The dig was thus able to demonstrate clearly that the present form of this monument through Platt Fields is the result of many phases of activity. Such a U-shaped, flared, ditch of roughly the same size, 4m to 4.5m wide and roughly 1.5m deep, can also be seen in the sections cut across Nico Ditch at Levenshulme, Reddish, and Audenshaw Lodge. At Audenshaw Lodge, Levenshulme and Reddish the pattern of activity was similar to that seen at Platt Fields with a primary cut followed by almost complete silting, before a much later series of re-cuts. The work at Longford Park did not locate the line of the ditch at this point, possibly due to landscaping. Frustratingly, no early dating evidence has been found at any of these sites, although the nature and extent of the fills of the primary ditch at Platt Fields indicated that it was of considerable antiquity. No evidence was found for a bank contemporary with this first ditch cut, whilst the existing bank to the north of the ditch was shown to be 20th century in origin.
Three theories have been suggested for the origin of Nico Ditch: territorial marker (as parish boundary or even as Roman centuriation); defensive structure (one tradition states that it was built in a day and night in the mid-9th century to fend off the Vikings); or drainage feature. In light of these excavations it would appear that the balance in evidence is shifting towards the territorial marker as the most likely origin of the monument. Indeed, the morphology of the primary ditch, with its gently sloping sides and flat base, is essentially inconsistent with the V-shaped ditches commonly used in antiquity for military purposes. This still leaves the problem of the archaeological context for this monument. In the absence of secure dating evidence we are forced to rely on historical and typological evidence, which suggests that this monument dates to either the early medieval or late prehistoric periods. If this is so then it falls within a group of roughly 50 such monuments belonging to these periods. Distributed widely throughout the country these earthworks range in size from those which extend for as little as a few hundred metres, to those which are immense, such as Offa’s Dyke on the Welsh border, Wansdyke in Wessex and Wat’s Dyke, again on the Welsh border. Commonly they are considered to have a duel functional, serving both defensive and administrative roles.
Over the last 30 years the problem of the original form and development of the monument has been addressed, and to some extent revealed, through machine-dug sections across Nico Ditch, although the overall length of the monument and the presence or absence of a bank along its full length have still to be established. The most pressing question still to be addressed is an accurate date for its construction. Radio-carbon dating has not been possible due to the disturbed nature of the sections investigated but the technique of optical luminescence dating offers hope that its primary date could yet be determined. Whilst we await an opportunity to test this, we have to be content with the occasional glimpse of this enigmatic monument as it struggles to survive the urban sprawl of 21st century southern Manchester.