Souterrain

The National Monuments Service's description

In Killala town, located in the SE quadrant of the graveyard (MA022-017010-) of the cathedral (MA022-017003-) and extending beneath the adjoining street at E. This is a multi-chambered souterrain of drystone construction with lintel roofing and earthen floors. The current access hole is in the base of a depression (diam. 4m; D 1m) encircled by a low concrete wall and wrought-iron railings. The access hole pierces the roof of a subcircular chamber; it is not the original entrance but the result of the partial collapse of the roof caused by grave digging in the 19th century (O’Hara and Westropp 1898, 291).
The subcircular chamber (2.9m N–S; 2.6m E–W; H c. 1.8-2m) has corbelled, drystone walls rising to a domed roof, capped with a flat lintel slab. A recess (L 1.2m E–W; max. Wth 0.43m; H c. 0.6m), with drystone side walls and an earthen end wall, is built into the wall above floor level on the W side of the chamber. At floor level on the E side of the chamber, a lintelled opening (Wth 0.62m at base, 0.4m at top; H 0.98m) leads into a lintel-roofed passage (Wth c. 70m; H 0.8m) which extends to ENE for c. 6m, at which point it is blocked. A cross-slab (MA022-017009-), reused as a roof lintel, is located in this passage. There are two lintelled openings from the E–W passage, one in the N wall and one in the S wall. The opening in the S wall is located at a point 4m E of the subcircular chamber. It is covered by a large, purpose-shaped lintel, and accesses a low, narrow passage or creep (Wth 0.37m) which extends for at least 2m to S, but is now largely infilled with soil. This may be the original entrance passage to the souterrain.
The opening in the N wall of the main E–W passage is located 2m E of the subcircular chamber. It accesses a short creep (L 1m N−S; Wth 0.6m; H 0.68m) which opens into the S end of a large, rectangular chamber (4.4m N−S; 2.1m E−W; H 1.5m). The walls of the chamber are vertical with large stone corbels protruding from the upper courses to support massive roof slabs. At the W end of the N wall, another short creep (0.7m N−S ; 0.5m E−W ; H 0.75m) leads N into the S end of a second rectangular chamber (4.85m N−S ; 1.8m E−W; H 1.75m), similar in construction, size and orientation to the first. There is a small recess in the W wall of this chamber. In the N wall, there is an alcove (1.95m N−S; 1m E−W; H 0.85m) located at a height of 1m above floor level. In the floor of the alcove, a square opening marks the location of what was originally a slab-covered, trapdoor entrance. It drops into a small, rectangular, chamber (1.45m N−S; 1.05m E−W; H 0.7m) concealed directly beneath the alcove. From the E wall of the concealed chamber, a short creep (0.65m E−W; 0.45m N−S) leads into the SW end of a third, large rectangular chamber (4m N−S; 1.65m E−W; H 1.55m), of similar construction to the other two.
The souterrain is frequently flooded as a result of a constant seepage of ground water. The souterrain, the cross-slab (MA022-017009-) and the nearby round tower (MA022-017001-) provide the principal visible evidence for an important Early Medieval ecclesiastical settlement in Killala.

Many of the measurements and morphological details in the above description are based on a survey and scale drawings of the souterrain completed in 1982 by Mr. Noel Dunne, archaeologist, assisted by Mr. Kevin Gilvarry.

Compiled by: Jane O'Shaughnessy

Date of upload: 13 July 2016

References

O'Hara, Mgr. and Westropp, T. J. 1898 Proceedings: The excursions. Journal of the Royal Society of Antiquaries of Ireland 28, 288-293