Souterrain in Castletowndelvin

This souterrain was discovered in 1999 in the course of construction works for a housing development. A survey of the monument was undertaken on 26-28 May 1999 and the following description is extracted from the accompanying report (Murphy 1999): ‘The souterrain consisted of a passage with two levels which terminated in a beehive shaped chamber. The entrance to the passage has been interfered with in recent years probably during the time of construction of the houses to the west of the souterrain. The passage extends in a roughly north-south direction and the chamber is located to the north and the entrance to the south. The gradual rise of the floor of the passage and the drop in the level of the roof towards the entrance would suggest that originally there was a creep in this area of the passage. However there is a large amount of spoil in this area and without excavation it is not possible to determine the exact type of entrance nor its dimensions. The passage (level one): This passage which was entered from the south, curved eastwards towards a drophole that provided access to a lower level (Level Two). The passage measured 3.2m in length and 0.85m in maximum width and 0.6m in minimum width. It had an average internal height from floor to roof lintel of 1 m, but as it extended southwards towards the entrance it decreased to a heigh: of 0.65m. At approximately 1.7m north of the entrance a roughly circular pit was cut into the floor of the passage. The pit measured 0.75m north-south and 0.6m east-west. It had an average depth of 0.23m. The floor of the passage consisted of an orange coloured sandy clay with occasional patches of charcoal and some animal bone. The walls of the passage were constructed of reasonably regular roughly cut greywacke blocks. Orthostats measuring 0.5m by 0.3m to 0.5m in width rested on the floor of the passage above which smaller stones were placed. These averaged 0.3m by 0.2m and the roof of the passage rested on these. The roof consisted of large flat lintels measuring almost lm in length by 0.7m in width. In total only 6 lintels spanned the roof distance of this passage (excluding the area over the drophole). The drophole was the main feature of the passage and it was located at the northern end. The drophole was rectangular in shape with a slightly semi-circular end which terminated under the northern wall of the passage. The walls above the drophole unlike the rest of the passage did not contain any large stones but instead were built from more regular stones of small to average size. The north wall of the passage corbelled inwards towards an exceptionally large lintel over the roof above the drophole area. The drophole was open when discovered and there was no evidence for a capstone or lintel that would have covered the floor area of level one and hence blocked access to level two. The drophole measured 2m in height from the floor of level two to the roof lintel of level one. The northern end of the passage widened considerably over the drophole to a maximum of 1,2m. The passage (level two): Level two consisted of a roughly north-south passage of 2.75m in length. It had an average width of 0.65m except at the southern end where it measured 0.75m below the drophole. It had an internal height from floor to roof lintel of 0.8/0.9m. The walls of level two were of similar construction to level one. The south wall of the passage below the drophole was constructed of average sized roughly hewn angular stones while the cast and west walls of the passage had larger stones similar to those encountered in level one. The passage was roofed with three large lintels and at the southern end below the drophole. The lintel or capping was missing. The floor of the passage consisted of orange sandy clay and it sloped upwards from 30.51m O.D. at the north of the passage to 30.71m O.D. at the south of the passage. It was also noted that charcoal patches were more frequent on the floor of this level and in the beehive chamber. Chamber: The chamber which was located at the northern end of the passage was accessed via level two. It was a beehive chamber constructed of dry stone with a corbelled roof. The base of die walls which rested on the floor of the chamber consisted of large orthostats of similar dimensions to those encountered in the passage. Above these however the roof was corbelled inwards using smaller more regular sized stones. Two flat lintels which originally capped the centre of the chamber had been removed by machine during the course of development The chamber measured 2.8m north-south and 2.82m east-west. The floor of the chamber was roughly square in shape except along the western side where it curved slightly. It had a maximum height of 1.37m from the centre of the floor of the chamber to the roof. The northern wall of the chamber corbelled inwards almost from floor level up while the southern wall was straight sided for the first metre before corbelling began. This was caused by the entrance to the passage on the southern side of the chamber.’ Compiled by: Paul Walsh Date of upload: 22 July 2014