The walk starts from the Ogwen Centre car park beside the A5 at the western end of Llyn Ogwen (LL57 3LZ), run by the Snowdonia National Park Authority. It costs £3 for 4 hours or £6 for the day, and the day ticket runs out at midnight. Most people take 3½ to 4½ hours on this loop, so the day ticket is the safer choice. Payment is by card or contactless only; cash isn't accepted. There are 2 blue badge spaces and EV charge points, and public toilets and a snack bar in the car park. Spaces are limited and fill up quickly at peak times; if it's full, see Alternative Parking. Check the latest prices here.

If you'd rather not drive up the valley, park at Bethesda Football Club car park (£7 a day) and take the Bws Ogwen electric minibus, or catch the TrawsCymru T10 bus, which stops at Ogwen.

Never park on the double yellow lines along the A5.

Perched above the drop of the mountain's eastern face, two pillars of rock crown Tryfan's summit, each about 3m high and 1.2m apart. In English they're Adam and Eve; in Welsh, Siôn a Siân. Stepping or jumping from one to the other has long been said to give you the Freedom of Tryfan.

One of the earliest recorded leaps was made by a country parson. Peter Bailey Williams, born in Carmarthenshire in 1763, became rector of Llanrug and Llanberis in 1792 and stayed there for the rest of his life. In 1798, while acting as a guide for the botanist William Bingley, he led what is thought to be the first recorded rock climb in Britain, probably on the East Terrace of Clogwyn Du'r Arddu on Snowdon. On another outing he took Bingley up from Cwm Idwal over Tryfan and the two Glyders, and on Tryfan's summit he gave his guest a fright by leaping from Adam to Eve.

More than two centuries on, the gap is no smaller. The writer Frank Showell Styles reckoned the step was not too hard on a calm, dry day, but that the price of getting it wrong would be about as unpleasant as it gets. The National Trust calls the leap dangerous and says it is only for those who try it at their own risk.

Medieval Welsh poets kept their own list of where the heroes of legend lie buried. Called the Englynion y Beddau, or Stanzas of the Graves, it survives in the Black Book of Carmarthen, copied in the 13th century, though scholars think some of its verses may have been composed in the 9th or 10th century. One of its stanzas says that the grave of Bedwyr is on the wooded slope of Tryfan.

In the earliest Welsh stories Bedwyr is one of King Arthur's greatest warriors. He's called Bedwyr Bedrydant, Bedwyr of the Perfect Sinew, and he's a one-handed warrior: a 10th-century poem, Pa gur, says enemies fell by the hundred before him. In the tale of Culhwch and Olwen he stands with Cei at the head of Arthur's court, carries a magic spear that makes nine wounds, and helps hunt down the great boar Twrch Trwyth.

Later writers turned him into Sir Bedivere. In Thomas Malory's Le Morte d'Arthur he stays with the dying Arthur after the last battle and is sent to throw Excalibur into the water. Twice he can't bring himself to do it, and when he finally does, a hand rises from the water, catches the sword and draws it under. Bedivere spends the rest of his days as a hermit. If the old poem is right, the knight who returned Excalibur lies somewhere on the mountain you've just climbed.