Anecdotally, for many years it was suggested that this large cave and smaller Drifts, (man-made tunnels connected to mining) visible from the Harbour, were in fact underground Adits taking water away from the Copper Mine on higher ground, but these are only short man-made interventions into the cliff side and totally unconnected. The two documented and recorded Copper Mine adits fed northwards from the mine below a shallow valley, into the river course directly below the Listed Mill on Mullion Mill Farm. From there the water flows into the Cove some away. With Torchlight Cave, sometimes referred to in the 19th century as the "Great Cave", being such an important site for visiting Victorian tourists, the fact that it is now so much more difficult to reach on foot- only for short periods during the lowest tides- it is therefore a strong indicator of a rising sea level, something which is so important for the future of the Mullion Harbour.