Un diwrnod oer a niwlog ym Mharc Cenedlaethol Eryri, roedd Rhys a Eleri yn barod am antur.

One cold and misty day in Snowdonia National Park, Rhys and Eleri were ready for adventure.

Roeddent wedi penderfynu mynd ar daith gerdded heriol ar hyd y llwybrau serth, yn chwilio am yr olygfa orau o gopaon y mynyddoedd.

They had decided to embark on a challenging hiking trip along steep paths, searching for the best views from the mountaintops.

Wrth iddyn nhw ddechrau, roedd y niwl yn trwchus ac yn cuddio popeth o'u cwmpas.

As they began, the fog was thick, concealing everything around them.

Roedd Eleri yn cerdded ychydig gamau y tu ôl i Rhys, ei chlywed yn chwerthin ac yn siarad â'i hun.

Eleri was walking a few steps behind Rhys, hearing him laughing and talking to himself.

Ond, ar un adeg, collodd Rhys olwg ar Eleri yn llwyr.

But at one point, Rhys completely lost sight of Eleri.

"Lle est ti, Eleri?

"Where are you, Eleri?"

" galwodd Rhys, ond dim ond sŵn y gwynt y clywodd yn ôl.

called Rhys, but all he heard in response was the sound of the wind.

Roedd wedi crwydro ychydig ymhellach a dechrau poeni pan welodd, yng nghanol y niwl, beth oedd yn ymddangos fel silwét Eleri yn sefyll yn sownd.

He had wandered a bit further and started to worry when he saw, in the midst of the fog, what appeared to be Eleri's silhouette standing still.

"Eleri, deffro!

"Eleri, wake up!

Dyma ni, yn y canol o rhywbeth mawr!

Here we are, in the middle of something big!"

" gwaeddodd Rhys wrth redeg tuag at y ffigur.

shouted Rhys as he ran toward the figure.

Ond wrth gyrraedd, dechreuodd Rhys chwerthin yn uchel.

But upon reaching it, Rhys began to laugh out loud.

Nid Eleri oedd yno o gwbl, ond dafad fawr, wyn a dawel yn bwyta ei glaswellt yn ddi-boen.

It wasn't Eleri at all, but a large, white, and quiet sheep peacefully eating its grass.

Roedd y niwl wedi twyllo llygaid Rhys.

The fog had deceived Rhys's eyes.

Yn fuan wedi hynny, daeth llais Eleri trwy'r niwl.

Soon after that, Eleri's voice came through the fog.

"Rhys, beth sy'n digwydd?

"Rhys, what's going on?

Pam wyt ti'n chwerthin?

Why are you laughing?"

" Galwodd Rhys yn ôl ati, gan egluro ei gamgymeriad doniol.

Rhys called back to her, explaining his amusing mistake.

Yn y diwedd, daeth y ddaear clir, a darganfyddodd Rhys a Eleri eu gilydd unwaith eto.

Finally, the earth cleared, and Rhys and Eleri found each other once again.

Wedi chwerthin am yr hyn oedd wedi digwydd, aethant ymlaen gyda'u taith, gan fwynhau'r harddwch cudd o Eryri.

After laughing at what had happened, they continued on their journey, enjoying the hidden beauty of Snowdonia.

Unwaith eto, roedd y mynyddoedd wedi rhoi stori i Rhys a Eleri fyddai'n parhau i'w chwerthin am flynyddoedd i ddod.

Once again, the mountains had provided Rhys and Eleri with a story that would continue to make them laugh for years to come.