Our posts so far have focussed on the broch’s interior, but now we turn our attention to the walls themselves and the features within. Intramural cells and galleries are characteristic of brochs, and Clachtoll displays a range of these. Excavating inside these cavernous spaces was quite an experience for archaeologists and volunteers alike, and you can hear Gordon Sleight of Historic Assynt describing his feelings on entering the passage for the first time below.
The entrance into the broch is topped with a massive triangular lintel, instantly recognisable and iconic of the monument. Although cleared out prior to the project starting at the broch, the entrance passage was filled with soft sediments and rubble left exposed and vulnerable by the rubble removal from the interior of the garth. A fragment of quern stone and a ceramic sherd were recovered from this deposit. Beneath these soft deposits, the flagstone covering of the drain discussed in our earlier post ran into the entrance passage directly for a length of around 2m, directly overlying the bedrock. The drain runs somewhat to the eastern side of the entrance passage, though this is considered to be serendipitous and simply a response to the landward-sloping bedrock, which drops away in this direction.
Cell 2 is the tallest intramural space in the broch. The cell is rather angular in plan, with straight ends aligned radially to the broch wall. Unusually, Cell 2 is accessed via an entrance doorway located c. 1m above the inner wall foot; once inside there is a step down into the interior of the cell c.1.5m below, suggesting that access to and from the cell was probably via a wooden ladder or steps. The character of the stonework of Cell 2 raises some suspicion that it may not have been part of the original design of the broch, or that it had witnessed significant rebuilding at some stage in the history of the broch’s use.
Within the deposits inside the cell was an unusual grey-blue organic layer with a mould-like, ‘fluffy’ texture suggesting decayed organics, as well as a thick deposit of burnt cereal grain and charcoal. The character of contexts will be evaluated in the post-excavation analysis stages, but it is possible that they represent the storage of foodstuffs in this area.
— AOC Archaeology (@aocarchaeology) August 4, 2017
Gallery 3: the stairs
Gallery 3 is located on the southern side of the broch. This intramural space is the largest of those surviving in the broch wall, comprising the stair to the first floor of the tower and encompassing a ground-level stair-foot cell running to the west for a distance of over 3.5m. The stair itself comprises thirteen steps ascending clockwise to the W, leading to a short surviving landing at first floor level. Prior to excavation commencing, Gallery 3 was filled close to the level of the wallhead with rubble debris and wind-blown sand. On removal of this material, it became clear that the majority of the soft sediment accumulation in this area was of relatively modern date, with the upper sandy deposit producing pieces of fishing float, fragments of plastic and a penny dating to 1944. Within this accumulated sand, several large, long sandstone blocks were removed from Gallery 3 and were interpreted as fallen lintels that originally spanned the gallery above head height.
At the foot of the stair, removal of the same rubble and sandy deposits encountered in the broch interior uncovered a steep step in the bedrock, over which Gallery 3 had been constructed; the lowest step was placed at the edge of this bedrock shelf, meaning that the floor space within Gallery 3 would have been uneven and presumably floored with timber or wicker to allow access. Within the upper sandy deposits at the foot of the stair, .
Cell 4, the guard cell to the right of the entrance passage was fully excavated. A somewhat disturbed flagstone floor was packed and levelled with a rubbly infill which lay within a thick deposit which displayed layering indicative of repeated refurbishment, likely in a similar manner to that undertaken within the broch interior .
During the removal of rubble from the seaward-side broken wall end prior to consolidation works, the vestigial remains of a probable further gallery, termed Gallery 5, were uncovered on the south wall end, indicating that a further intramural cell had been located on the west side of the broch. It is probable that this cell was accessed from a doorway located close to the 3 o’clock position within the broch, within the segment of walling now lost to coastal erosion, but too little of the cell remained to establish more of its character.
This is the last of our posts focussing on the layout of the broch – next up, finds and faunal remains! The post will go up a week today, but you can sign up to receive these posts straight to your inbox using the form in the right sidebar.