Archaeological Survey
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FAS EILEAN DONAN CASTLE ROSS-SHIRE ARCHAEOLOGICAL SURVEY JULY 2008 ARCHAEOLOGICAL SURVEY EILEAN DONAN CASTLE ROSS-SHIRE SITE CODE: LDC08 REPORT CODE: FAS2008 404 LDC342 NGR: NG 8812 2583 Monument No: 7575 REPORT July 2008 Registered in England No. 2801722 VAT Registration No. 599 0974 69 FIELD ARCHAEOLOGY SPECIALISTS LTD Unit A3 Parkside Centre TELEPHONE (01904) 652000 Terry Avenue FACSIMILE (01904) 656222 York YO23 1JP [email protected] ON BEHALF OF MACKENZIE KERR Redwood 19 Culduthel Road Inverness IV2 4AA CLIENT THE CONCHRA CHARITABLE TRUST PROJECT TEAM Justin Garner-Lahire BA Richard Jackson BA Nicola Toop BA MA PhD REPORT PREPARED BY Nicola Toop BA MA PhD REPORT REVIEWED BY Cecily Spall BSc MA REPORT AUTHORISED BY Jonathan Clark BA MA DPhil Registered in England No. 2801722 VAT Registration No. 599 0974 69 FAS2008 404 LDC342.wpd i LIST OF CONTENTS Contents Page Summary v Acknowledgements v 1.0 INTRODUCTION 1 1.1 LOCATION AND LAND USE 1 1.2 AIMS AND OBJECTIVES 1 1.3 ARCHAEOLOGICAL AND HISTORICAL BACKGROUND 1 1.3.1 Prehistory 1 1.3.2 Early medieval period 3 1.3.3 Medieval period 3 1.3.4 18th-century demolition 10 1.3.5 20th-century reconstruction 11 1.3.6 Modern use 13 2.0 SURVEY PROCEDURE 13 2.1 SURVEY GRID 14 2.2 TOPOGRAPHIC SURVEY 14 2.3 GEOPHYSICAL SURVEY 14 2.3.1 Soil resistance survey 14 2.3.2 Magnetometer survey 14 3.0 SURVEY RESULTS 20 3.1 TOPOGRAPHIC SURVEY 20 3.1.1 Zone 1 20 3.1.2 Zone 2 20 3.1.3 Zone 3 23 3.1.4 Zone 4 26 3.1.5 Zone 5 27 3.1.6 Zone 6 and 7 28 3.2 SOIL RESISTANCE SURVEY 28 3.2.1 Area A 28 3.2.2 Area B 32 3.2.3 Area C 32 3.3 MAGNETOMETER SURVEY 32 3.3.1 Area A 34 FIELD ARCHAEOLOGY SPECIALISTS FAS2008 404 LDC342.wpd ii 4.0 DISCUSSION 34 4.1 VITRIFIED FORT 34 4.2 CASTLE DEFENCES 35 4.2.1 Towers 35 4.2.2 Curtain wall and outer ward 37 4.2.3 Layout and development of the castle 37 4.3 20TH-CENTURY RECONSTRUCTION 38 4.3.1 Boundary wall 38 4.3.2 Topographic alterations and clearance 38 4.3.3 Tracks 38 4.3.4 Middens 39 5.0 ASSESSMENT 39 5.1 ZONE 1 39 5.2 ZONE 2 39 5.3 ZONE 3 40 5.4 ZONE 4 40 5.5 ZONE 5 41 6.0 FURTHER EVALUATION 41 References Figures 1 Location map 2 2 Survey area 15 3 Contour map at 0.5m intervals 16 4 Detailed contour map at 0.2m intervals 17 5 Location of geophysical survey areas 18 6 Zone map 21 7 Zone 1 22 8 Topographic interpretation - Zones 3, 4 and 5 24 9 Soil resistivity results 0.5m probe separation 29 10 Soil resistivity results 1.0m probe separation 30 11 Geophysics interpretation 31 12 Gradiometry results 33 13 Archaeological interpretation 36 FIELD ARCHAEOLOGY SPECIALISTS FAS2008 404 LDC342.wpd iii Plates 1 Eilean Donan Castle from the northeast 1 2 Pre-1908 view of the castle (GWW E1606) 3 3 Vitrified rock at the castle 3 4 Plan and elevation by Lewis Petit 1714 (RCD 68/1) 6 5 Plan by MacGibbon and Ross, 1889 7 6 Miket and Roberts’ current plan of the castle (1990, 81) 7 7 Miket and Roberts’ First Phase (1990, 82) 7 8 Miket and Roberts’ Second Phase (1990, 83) 8 9 Miket and Roberts’ Third Phase (1990, 89) 8 10 Brass guns found at the site (Miket and Roberts 1990, 88) 9 11 Topographic survey in progress 14 12 Soil resistance survey in progress 14 13 Zone 2 - general view from the east 23 14 Zone 2 - Macrae memorial 23 15 Zone 3 from the south 23 16 Zone 3 from the east 23 17 Zone 3, Feature 1 25 18 Zone 3, Feature 1, from the south 25 19 Zone 3, Feature 2 25 20 Zone 3, Feature 3 25 21 Zone 3, Feature 4 and 5 26 22 Zone 3, Feature 6 and 7 26 23 Zone 4, from the southeast 26 24 Erosion at the western edge of Zone 4 26 25 Zone 4, Feature 8 27 26 Zone 4, Feature 8, exposed masonry 27 27 Zone 4, Feature 9 27 28 Zone 4, Feature 10 27 29 Zone 5 and 6 28 30 Zone 7 28 31 Eilean Donan during reconstruction, 1929 35 32 Extract from Ordnance Survey, 1879 35 33 Photograph from the southeast, c.1890 38 34 Zone 4 from the east 39 35 Tree roots and extant masonry 40 FIELD ARCHAEOLOGY SPECIALISTS FAS2008 404 LDC342.wpd iv Tables 1 Summary of zones 20 Appendices A Contour map at 0.5m intervals B Contour map of island at 0.2m intervals C Raw data plots - soil resistance D Raw data plots - gradiometry FIELD ARCHAEOLOGY SPECIALISTS FAS2008 404 LDC342.wpd v Summary An archaeological survey, consisting of topographic and geophysical survey, was undertaken at Eilean Donan Castle, Ross-shire, by Field Archaeology Specialists (FAS) Ltd on behalf of Mackenzie Kerr for the Conchra Charitable Trust. The survey was carried out between 2nd and 14th March 2008. The topographic survey has provided a detailed contour map of the island and immediate surroundings, in addition to an outline survey of the extant castle structures. The survey has also allowed a detailed plan to be drawn up of those elements of the castle defences which survive as earthwork features and have been previously planned only in sketch form. Geophysical survey (soil resistance and magnetometry) revealed further information relating to the buried curtain wall and towers of the castle defences, in addition to a number of as yet unidentified below-ground features. A number of 20th-century features, including a path from the castle to the jetty, were also defined. Acknowledgements Field Archaeology Specialists would like to thank the Trustees of the Conchra Charitable Trust and David Win for their kind assistance during the course of the fieldwork. We would also like to thank Laura Hindmarch, Historic Scotland, for her support and advice. FIELD ARCHAEOLOGY SPECIALISTS FAS2008 404 LDC342.wpd 1 1.0 INTRODUCTION This document reports on a topographic and geophysical survey undertaken by Field Archaeology Specialists (FAS) Ltd on behalf of Mackenzie Kerr for the Conchra Charitable Trust. The survey was carried out at Eilean Donan Castle between the 2nd March 2008 and 14th March 2008. 1.1 LOCATION AND LAND USE The castle of Eilean Donan lies at the confluence of three lochs on the western seaboard of Scotland, situated on a small island, now connected to the mainland by a bridge (Figure 1; NGR: NG 8812 2583). Although the site of a medieval fortification, the current appearance of Eilean Donan is primarily the result of an early 20th-century campaign of reparation and restoration, undertaken by Lieutenant-Colonel John Macrae Gilstrap. The picturesque nature of the monument and its surroundings has made the site a major tourist destination, attracting thousands of visitors per year (Plate 1). 1.2 AIMS AND OBJECTIVES The topographic survey was carried out with the aim of creating an accurate map of the island and its immediate context, and to identify any features of archaeological interest on the island itself. The survey would Plate 1 Eilean Donan castle from the northeast also provide a detailed base map for any future archaeological investigation of the island. The geophysical survey (soil resistance and magnetometry) aimed to accurately locate sub-surface geophysical anomalies in accessible parts of the island. An assessment of the survey data and interpretation of geophysical anomalies aimed to characterise the buried archaeological environment across the island, to enhance understanding and inform future investigation and management of the site. Specifically, the survey aimed to create as accurate a plan as possible of the castle defences, and to identify any possible structures within the outer bailey area. In addition, the magnetometry aimed to confirm the presence or absence of a vitrified fort at the site. 1.3 ARCHAEOLOGICAL AND HISTORICAL BACKGROUND An assessment of the known historical and archaeological development of Eilean Donan Castle was undertaken in 2006, and what follows represents a summarised version of these findings. 1.3.1 Prehistory It is frequently stated that Eilean Donan Castle was constructed on the site of a vitrified fort (Gifford 1992, 533n). Prior to the reconstruction works of the 1920s and 1930s, Wallace observed that: FIELD ARCHAEOLOGY SPECIALISTS FAS2008 404 LDC342.wpd 3 ‘on the landward side of the Island are traces of a vitrified wall of considerable dimensions, indicating probably that the island had been the site of a prehistoric fort’ (Wallace 1912-1918, 109) Wallace was referring to a length of collapsed walling, some 55m long, situated on the eastern shore of the island, and visible on late 19th- and early 20th-century photographs of the site (Plate 2). Although vitrified rock is known to have occurred within this construction, and has been retained at the site (Plate 3), the antiquity of the wall itself has been called into doubt; it has been suggested that the fragments could equally have been reused in a relatively modern feature (CANMORE 1974). Plate 2 Pre-1908 view of the castle (GWW E1606) 1.3.2 Early medieval period Eilean Donan translates as ‘Island of Donnan’, and has been readily associated with the early medieval saint, Donnan (or Donan) of Eigg (Miket and Roberts 1990, 74, 80).