Man-made underground passage in Rafarn (kilmeen Ed)

Ten metres eight of black earth stretch north beneath the rath, wide enough for two people to walk shoulder to shoulder and deep enough to swallow a standing man. The dimensions suggest deliberate digging rather than animal damage, though no entrance, chamber or purpose has survived to explain the labour. Perhaps the passage led to water, a cache or a hidden room now collapsed; perhaps it was abandoned before it was finished. In either case, someone measured the dark, cut through solid ground and left a long empty tunnel waiting for a destination nobody remembers.