Approaching Killawalla from the Ballintubber side not far away from the village there is an Old Mill, which is located on the river Aille. The mill was built in the 19th century by Lord Avonmore and was used for grinding corn or milling flour. The mill was forced to close due to a dispute between Avonmore and another local landlord Lord Lynch Bosse. The dispute was over who owned the land either side of the river. Even building a canal to the mill was not able to supply water to the mill and it consequently became abandoned.
Close to Killawalla there is an ancient Crannog. Crannogs are man-made islands, usually located in marshy areas or small lakes. They could be accessed from surrounding mainland by use of submerged causeways or small boats. They were built for homesteads or used as cattle pens and safe houses. During the time of the Celts, cattle were the main unit of currency and therefore were very valuable. Cattle were often stolen in cattle raids and crannogs were one method of cattle protection.