The Nant Ffrancon Pass in Snowdonia, North Wales, is the long steady climb of the A5 road between Bethesda, Gwynedd, and Llyn Ogwen in Conwy. The summit at 312 metres (1,024 ft) is at Pont Wern-gof, about one-third of a mile beyond the eastern end of Llyn Ogwen. From here the road descends through Nant y Benglog to Capel Curig and through to Betws-y-Coed. The A5 is the Holyhead to London trunk road, which was re-engineered by Thomas Telford between 1810 and 1826. The original road through the Nant Ffrancon was constructed by Lord Penrhyn in the late 18th century, and at Capel Curig in 1801 he built a coaching inn, which is now Plas y Brenin, the UK National Mountaineering Centre.