Overview
- A widely shared image shows a dramatic-looking cavity on a slope north of Abergynolwyn in the Dysynni Valley, Eryri (Snowdonia).
- Local reports and on-the-ground observers point to sun angle and shadowing that exaggerate a broad natural depression roughly 100 metres wide with a seasonal stream.
- The dark “smoke” in the image is described as shifting micro-shadows rather than any plume from fire or activity.
- Alternative theories are discounted: the Bryn Eglwys slate quarry lies on the valley’s opposite side, and the documented Flying Fortress crash site is near Craig Cwm Llwyd, not at this location.
- No official probe is reported, and the feature sits within a landscape rich in archaeology, including Craig Ty'n-y-Cornel and views toward the Craig yr Aderyn hillfort.