847 Dinas Dinlle Hillfort Llandwrog Archaeological Watching Brief GAT Project No. 2118 Report No. 847 Feb 2010 Ymddiriedolaeth Archaeolegol Gwynedd Gwynedd Archaeological Trust Craig Beuno, Ffordd y Garth, Bangor, Gwynedd, LL57 2RT Archaeological Watching Brief: Dinas Dinlle, Llandwrog Report No. 847 Prepared for The National Trust February 2010 Cover: Dinas Dinlle Hill Fort and WWII Seagull Trench from the North By Matt Jones & Robert Evans Ymddiriedolaeth Archaeolegol Gwynedd Gwynedd Archaeological Trust Craig Beuno, Ffordd y Garth, Bangor, Gwynedd, LL57 2RT DINAS DINLLE, LLANDWROG ARCHAEOLOGICAL WATCHING BRIEF Project No. G2118 Gwynedd Archaeological Trust Report No. 847 &217(1763DJH 6XPPDU\ ,QWURGXFWLRQ 6SHFLILFDWLRQDQG3URMHFW'HVLJQ 0HWKRGVDQG7HFKQLTXHV 7RSRJUDSK\DQG*HRORJ\ $UFKDHRORJLFDO%DFNJURXQG 5HVXOWVRIWKH:DWFKLQJ%ULHI &RQFOXVLRQ $UFKLYH 6RXUFHV&RQVXOWHG FIGURES Fig. 1/RFDWLRQRI1HZ)HQFLQJDQG3DWKZD\DW'LQDV'LQOOH PLATES Plate 1,QWHULRURI'LQDV'LQOOH+LOO)RUW6KRZLQJ)HQFH/LQH Plate 2 :HVWHUQ%DQNVRIWKH)RUW)DFLQJ:HVW Plate 3 +DQG3ODFHPHQWRI3RVWV Plate 4 0HFKDQLFDO3RVW3ODFHPHQW Plate 5 'DUNHU5HGHSRVLWHGVRLOFRQVROLGDWLRQPDWHULDOEURXJKWLQWRVWDELOL]H DQGSURWHFWUDPSDUWVSULRUWRWKHOD\LQJRIWKHSDWKZD\ Plate 6 *HQHUDO9LHZRI+LOO)RUWIURPWKH1RUWK6KRZLQJ(URGLQJ&RDVWOLQH Summary Dinas Dinlle,, a substantial late prehistoric hill fort located on an isolated hill of glacial drift, has a coastal location overlooking Caernarfon Bay south of Caernarfon, within an area of land managed by the National Trust. The site has been subject to extensive coastal erosion and also visitor erosion. To improve visitor access and to minimise foot erosion two schemes have been put in place, consisting of a fence to protect the cliff face, and a path way across the monument. The watching brief monitored both the instillation of a reinforced foot path through the monument and the fencing off of the coastal edge. This was designed to create a safe environment and to enable the possibility of using the land for grazing The fence posts were all driven into the ground, so no new archaeological deposits were observed as a result of the erection of the new fencing. The new path was constructed upon new make-up material, so no archaeological deposits were affected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cot Trax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ntroduction 7KHKLOOIRUWDW'LQDV'LQOOH 351 LVD6FKHGXOHG$QFLHQW0RQXPHQW 5HI&2 ,WLV FXUUHQWO\WKHSURSHUW\RIWKH1DWLRQDO7UXVW$JHRSK\VLFDOVXUYH\ZDVFDUULHGRXWRQWKHVLWHLQ 6PLWK DOWKRXJKQRH[FDYDWLRQZRUNKDVEHHQFDUULHGRXW7KHVLWHKDVHURGHGVLJQLILFDQWO\ DERYHWKHFOLIIDORQJLWVZHVWHUQHGJHDVDUHVXOWRISHGHVWULDQDFFHVVDQGKDVDOVRVXIIHUHGIURP VLJQLILFDQWFRDVWDOHURVLRQ 5.2 Archaeological Background 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Survey (taken from Smith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Caerns. Hist. Soc 5&$+0:An Inventory of the Ancient Monuments in Caernarvonshire. Vol II: Central /RQGRQ 6PLWK%DQG*HRUJH71British Regional Geology; North Wales /RQGRQ 6PLWK*+A Survey of Prehistoric Defended Enclosures in North West Wales 2004-5 (West Conwy, Gwynedd (Arfon) and Anglesey Part 1: Survey Report XQSXEOLVKHG*$75HSRUW1R 6RLO6XUYH\RI(QJODQGDQG:DOHVSoils of Wales Coflein: RCAHMW on-line database Gwynedd Historic Environment Record Fig. 1 Location of New Fencing and Pathway at Dinas Dinlle (taken from NationBM Trust Drawing) Plate 1 Interior of Dinas Dinlle Hill Fort, Facing East, showing Fence Line Plate 2 Western Banks of the Hill fort, Facing West Plate 3 Hand Placment of Fence Posts Plate 4 Mechanical Post Placement Plate 5 Redeposited soil, consolidation material brought in to stabilize and protect ramparts prior to laying pathway Plate 6 General View of Hill Fort from the North, Showing Eroding Coastline 9-$$)2)%$/,!%4( '79.%$$ !2#(!%/,%'/, !2#(!%/,/')#!, '79.%$$ 42534 #RAIG"EUNO &FORDDY'ARTH "ANGOR 'WYNEDD,,24 &FON&FACSEMAILGAT HENEBCOUK.