Clach Toll Broch, Assynt Conservation Management Plan AOC 20867 March 2009 © AOC Archaeology Group 2009 Clach Toll Broch, Assynt, Sutherland Conservation Management Plan On Behalf of: Historic Assynt c/o Robin Noble Glenleraig Drumbeg By Lairg Sutherland IV27 4NJ National Grid Reference (NGR): NC 0366 2784 AOC Project No: 20867 Prepared by: Graeme Cavers Dimitris Theodossopoulos John Barber Andy Heald Juha Marttila Illustration by: Graeme Cavers Gemma Hudson Graeme Carruthers Date of Report: March 2009 This document has been prepared in accordance with AOC standard operating procedures. Author: Date: Approved by: Date: Draft/Final Report Stage: Date: Enquiries to: AOC Archaeology Group Edgefield Industrial Estate Edgefield Road Loanhead EH20 9SY Tel. 0131 440 3593 Fax. 0131 440 3422 e-mail. [email protected] www. aocarchaeology .com Clach Toll Broch, Assynt: Conservation Management Plan Contents Page List of illustrations ............................................................................................................................................................ 4 List of plates ...................................................................................................................................................................... 5 Executive Summary .......................................................................................................................................................... 7 Part One: The Archaeological significance of Clach Toll broch ................................................................................... 9 The brochs of Sutherland ................................................................................................................................... 9 Sutherland, Atlantic Scotland and frontier zones ............................................................................................... 9 Archaeological overview of Clachtoll ................................................................................................................ 10 Part Two: Clach Toll Broch, map regression ................................................................................................................ 11 Part Three: Clach Toll Broch, Condition Survey .......................................................................................................... 12 General description ........................................................................................................................................... 12 The Survey ....................................................................................................................................................... 12 Numbering system used in this document........................................................................................................ 12 The Broch Wall: exterior areas ......................................................................................................................... 13 The Broch Wall: interior areas .......................................................................................................................... 14 The rubble interior ............................................................................................................................................. 15 The entrance passage ...................................................................................................................................... 15 The intra-mural galleries ................................................................................................................................... 15 Other internal features ...................................................................................................................................... 16 External features ............................................................................................................................................... 16 Later features .................................................................................................................................................... 17 Condition: General observations ...................................................................................................................... 17 Part Four: Analysis of the broch structure ................................................................................................................... 19 Processes of destruction .................................................................................................................................. 19 Structural and conservation issues ................................................................................................................... 19 The structural character of the broch ................................................................................................................ 20 Understanding the monument: recommended avenues for research .............................................................. 21 Structural condition appraisal ........................................................................................................................... 22 Understanding the structural stability of the site: recommended action ........................................................... 23 Risk assessment and immediate priorities ....................................................................................................... 23 Archaeological and strengthening works .......................................................................................................... 23 Part Five: Archaeological Potential of the Broch ................................................................................................ 25 Depth of deposits .............................................................................................................................................. 25 Current social and cultural importance of the site ............................................................................................ 25 Part Six: Conservation Recommendations ................................................................................................................... 27 Conservation planning ...................................................................................................................................... 27 Philosophy and terminology ............................................................................................................................. 27 Priorities for conservation ................................................................................................................................. 28 The Threats to the monument .......................................................................................................................... 28 The sea ............................................................................................................................................................. 28 Stone robbing ................................................................................................................................................... 28 Natural decay .................................................................................................................................................... 28 © AOC Archaeology 2008 | PAGE 3 OF 41 | www.aocarchaeology.com Clach Toll Broch, Assynt: Conservation Management Plan Erosion due to human activity .......................................................................................................................... 28 Scale of threat and damage ............................................................................................................................. 29 Conservation principles .................................................................................................................................... 30 Phase 1: Emergency works of stabilisation and site management ................................................................. 30 The entrance area ............................................................................................................................................ 30 Proposal ............................................................................................................................................................ 30 The Wall Head .................................................................................................................................................. 31 Prevention of burrowing by rabbits and other animals ..................................................................................... 31 Control and management of visitor access ...................................................................................................... 31 Phase 2: Exploratory and interim works ........................................................................................................... 32 Research and conservation .............................................................................................................................. 32 Understanding the masonry fabric of the monument ....................................................................................... 32 Testing .............................................................................................................................................................. 32 Accommodation to variation in foundation levels ............................................................................................