Ogof Hesp Alyn

Ogof Hesp Alyn (Welsh for: Dry Alyn Cave) was discovered by North Wales Caving Club in 1973 in the Alyn Gorge near Cilcain, Flintshire, Wales. Reaching the end of the cave is a serious commitment requiring one pitch series and the draining of two sumps.

With more recent discoveries, the length of cave passage totals 2 kilometres (1.2 mi) extending over a vertical range of about 90 metres (300 ft). The entrance would have functioned as a rising prior to the lowering of local water levels by mine drainage. As drainage only took place in the early 20th century, Ogof Hesp Alyn provides a valuable opportunity to study a cave system developed almost entirely by a phreatic processes which remains largely unmodified by vadose streams.

It lies close to another cave, Ogof Hen Ffynhonnau, which lies about 150 metres (160 yd) further upstream in the Alyn Gorge. These two caves with Ogof Nadolig form the caves part of the Alyn Valley Woods and Alyn Gorge Caves SSSI.

References

• Appleton, Peter (1974). "Subterranean courses of the River Alyn, including Ogof Hesp Alyn, North Wales". Transactions of the British Cave Research Association 1: 29–42. 

• Appleton, Peter (1989). "Limestones and Caves of North Wales". In Ford, Trevor D.(ed.). Limestones and Caves of Wales. Cambridge University Press. pp. 233–7. ISBN 0-521-32438-6. 

• Waltham, A.C., Simms, M.J., Farrant, A.R., Goldie, H.S. (1997). Karst and Caves of Great Britain. Chapman & Hall, 2-6 Boundary Row, London SE1 8HN, UK. pp. 262–4. ISBN 0-412-78860-8. 

External links

• North Wales Caving Club
• Countryside Council for Wales
• http://www.cowdery.org.uk/hesp.php