Ardnacross was ideally sited for occupation by prehistoric people. It is fertile ground, near to the sea, a source of food and access to other coastal communities, its importance is underlined by the number of Bronze Age sites (2600-600BC) in a relatively small area. On a platform above and to the WSW of the Stables there are three kerb cairns and two parallel rows of three standing stones.
To east of the road 400 yards NNE of the farm is another cairn, in which the kerb consists of large stones up to three feet in height. Two more cairns are to be found above the shore on Rubh’ an t-Sean Chaisteil and just south of these cairns is the remains of a broch which would be of an Iron Age date (500BC-500AD). The broch is in a very ruinous state and only the base of the thick walls, and some of the entrance can be identified. Rubh’ an t-Sean Chaisteal translates as the ‘Point of the old castle ‘probably relating to the broch. A seventh burial cairn lies some 500yds to the South of the farm and is less well defined than the others.
Brochs are circular dry stone forts mostly concentrated in the north and west of Scotland (Ardnacross is somewhat south of the main area). They were built roughly 100BC to 100AD and are also characterised having hollow walls with staircases and small cell like chambers.
The north of Mull is remarkable in that there are seven sites with standing stone rows consisting of three to five stones. These stone settings excited the interest of the archeoastronomers, and after excavating the site at Glengorm in 1987-88, Dr Martlew & Prof. Ruggles, excavated and surveyed the Ardnacross site Standing Stone, during the summers of 1989 &1991. In 658 the Edict of Nantes, exhorted Christians to ‘dig up and hide pagan stones’, and it was found that the stones at the ends of each row had been pulled over and partly buried, maybe as a result of this.
The excavations revealed a date of 1260 to 910 BC which is a late date for stone rows. A small bracelet was recovered from close to one of the stones. It was of a copper alloy but interaction with the soil had leached out the metal, it is of unusual design with geometrical lines and chevrons.