Roedd hi'n ddiwrnod braf a heulog yng Nghastell Conwy, lle roedd pobl yn crwydro'r muriau a mwynhau'r olygfa.

It was a beautiful and sunny day at Conwy Castle, where people were wandering the walls and enjoying the view.

Eleri, merch ifanc gyda gwallt melyn a llygaid mor las â'r awyr uwch ei phen, oedd yn cerdded ar hyd y muriau uchel, ei hufen iâ mewn un llaw a chamera yn y llaw arall.

Eleri, a young girl with blonde hair and eyes as blue as the sky above her, was walking along the high walls, an ice cream in one hand and a camera in the other.

Ar yr un pryd, roedd Gethin, dyn ifanc cryf ag esgidiau mawr a het ddu, hefyd ar daith yr un ffordd.

At the same time, Gethin, a young man with strong arms and big boots, and a black hat, was also on the same path.

Wrth gerdded, roedd y ddau yn edmygu gweddillion yr hen gastell a'r golygfeydd anhygoel o'r môr a'r tir o'u cwmpas.

As they walked, both admired the remnants of the old castle and the incredible views of the sea and land around them.

Ond, wrth groesi cornel gul lle'r oedd y muriau'n cyfarfod, fe wnaeth rhywbeth rhyfedd ddigwydd.

But, when they reached a narrow corner where the walls met, something strange happened.

Gyda dim ond eiliad i ymateb, fe wnaeth Eleri a Gethin daro eu penau'n sydyn iawn.

In a split second, Eleri and Gethin both bumped their heads.

O'r holl bethau i'w cwympo, fe wnaeth hufen iâ Eleri syrthio'n ddirgelaidd o'i llaw ac, fel pe bai hud yn y gwaith, glanio'n berffaith yng nghongl Gethin yn lle ei het.

Of all things to fall, Eleri's ice cream fell distressingly from her hand and, as if by magic, landed perfectly in Gethin's hat instead.

Gethin, meddwl mai dim ond gwynt oedd y daflu, parhaodd i fynd heb sylwi ar y newid.

Thinking it was just a gust of wind, Gethin continued on without noticing the change.

Eleri, yn llawn sioc ac yn embaras, gan fod ganddi het Gethin yn ei dwylo'n gwbl anfwriadol, rhedodd ar ôl Gethin.

Eleri, full of shock and embarrassment, with Gethin's hat in her hands entirely unintentionally, ran after Gethin.

"Gethin! Gethin!" llefodd Eleri yn gryf, gan geisio ei dal.

"Gethin! Gethin!" Eleri shouted loudly, trying to catch him.

Trodd Gethin o'r diwedd, yn ddryslyd wrth weld merch ifanc yn dal ei het gyda hufen iâ yn gludo ati.

Finally, Gethin turned around, puzzled to see the young girl holding his hat with ice cream in it slinking towards him.

"Be'... be' sy'n digwydd?" gofynnodd Gethin gyda gwên ofnadwy.

"What...what's happening?" asked Gethin with a dreadful smile.

Eleri, gyda chywilydd a gwên ar ei hwyneb, estynnodd y het tuag ato, "Rwy'n credu bod hyn yn perthyn i ti," meddai, "a dy hufen iâ... wel, mae'n edrych yn wahanol iawn nawr."

Eleri, with embarrassment and a smile on her face, handed the hat to him, "I think this belongs to you," she said, "and your ice cream... well, it looks very different now."

Chwarddodd Gethin wrth iddo sylwi ar y sefyllfa doniol.

Gethin chuckled as he noticed the amusing situation.

Gyda chymeradwyaeth o'r hyfrydwch annisgwyl, fe wnaeth y ddau benderfynu eistedd lawr wrth ymyl crynhoi o gerrig, yn cysgodi o'r haul.

With a sense of unexpected delight, the two decided to sit down next to a pile of rocks, shaded from the sun.

Prynnodd Gethin hufen iâ newydd i Eleri, ac fe fuon nhw'n rhannu straeon a chwerthin am weddill y prynhawn yn edrych dros y dref fechan a'r afon.

Gethin bought Eleri a new ice cream, and they shared stories and laughter for the rest of the afternoon, looking over the small town and the river.

Ac, er bod yr hufen iâ wedi'i chwythu a'r het wedi cael blas arni, daeth yr hanes yn adroddiad o gyfeillgarwch a gwên.

And although the ice cream had melted and the hat had a taste of it, the story became a tale of friendship and smiles.

Yn y diwedd, yn yr olygfeydd hyfryd o Gastell Conwy a'i muriau, roedd etifeddiaeth newydd wedi'i seilio: stori am gyfnewid anfwriadol ond bythgofiadwy rhwng Eleri a Gethin, a dechreuad antur sychedig am gyfeillgarwch.

In the end, in the delightful sights of Conwy Castle and its walls, a new legacy had been cemented: a story of an unintentional but unforgettable exchange between Eleri and Gethin, and the start of a thirsty adventure for friendship.