Ar noson dywyll a stormus, gyda'r gwynt yn chwythu yn wyllt o gwmpas corneli tref Caerffili, roedd grŵp o bobl yn cychwyn ar daith ysbrydion yn nhrwm eiconig Castell Caerffili.

On a dark and stormy night, with the wind blowing wildly around the corners of the town of Caerphilly, a group of people set off on a ghost tour in the shadow of the iconic Caerphilly Castle.

Yn eu plith oedd Rhys, dyn ifanc sydd â diddordeb mawr mewn hanes a chwedlau.

Among them was Rhys, a young man with a great interest in history and legends.

Wedi'i hwyluso gan Gwen, arbenigwr ar chwedlau'r castell, a'i chymar Evan, dechreuodd y daith ym myd tywyll a misteriws y castell hynafol.

Facilitated by Gwen, an expert on castle legends, and her colleague Evan, the tour began in the world of darkness and mysteries of this ancient castle.

Roedd pob twll a chornel y castell yn dod yn fyw gyda'r straeon a'r chwedlau a adroddwyd gan Gwen, ac roedd awyrgylch y lle yn gwneud i ronynnau'r croen godi.

Every nook and cranny of the castle came alive with the stories and legends told by Gwen, and the atmosphere of the place made the hairs on the back of the neck stand up.

Wrth aros yng nghysgodion y neuadd fawr, sibrydodd Rhys wrth Evan, "Fedri di gredu'r straeon hyn?"

While waiting in the shadows of the great hall, Rhys whispered to Evan, "Can you believe these stories?"

Llygadwyd Evan yn gyfrinachol ato cyn iddo ateb, "Mae'n rhaid bod rhywfaint o wir yn nhw, on'd oes?"

Evan looked secretive before answering, "There must be some truth to them, don't you think?"

Yna, wrth iddynt grwydro ymhellach i galon y castell, cyrhaeddodd y grŵp i'r dwnjan.

Then, as they wandered further into the heart of the castle, the group reached the dungeon.

Roedd y lle yn oer, dan ei sang, a'r mwgwd o leithder yn teimlo'n drwm yn yr awyr.

The place was cold, damp, and the thick smoke of darkness felt heavy in the air.

Sylwodd Gwen ar fwgwd trwchus y tywyllwch. "Dyma ble y cedwid carcharorion y castell," meddai'n ddistaw, llais yn atseinio yn erbyn y waliau garw, carreg farw.

Gwen noticed the dense smoke of the darkness. "This is where the castle's prisoners were kept," she said quietly, her voice echoing against the rough walls, dead stone.

"Maent yn dweud eich bod yn gallu clywed sŵn cadwyni hyd heddiw."

"They say you can still hear the chains rattling to this day."

Roedd Rhys yn chwilfrydig, yn ysu i archwilio.

Rhys was curious, eager to explore.

Gadael y grŵp am funud fach, cerddodd i gornel dywyll y dwnjan.

Leaving the group for a moment, he walked to a dark corner of the dungeon.

Roedd sŵn y storm bellach yn edrych fel y sŵn o alwad sibrydion o'r gorffennol.

The sound of the storm now looked like the sound of calls from the past.

Wrth droedio'n ofalus, a heb sylwi bod y drws yn cymryd ei bwysau, daeth yn sownd y tu ôl iddo.

As he stepped carefully, without noticing that the door was taking its weight, it slammed shut behind him.

Pan ddaethant i sylwi bod Rhys ar goll, roedd Gwen a'r gweddill yn poeni.

When they noticed that Rhys was missing, Gwen and the others worried.

Dechreuodd Evan galw am Rhys, ond dim ond yr eco o'i lais ei hun a ddaeth yn ôl ato.

Evan began calling for Rhys, but only the echo of his own voice came back to him.

Ar y cyfle gorau, wrth i bawb benderfynu dychwelyd i chwilio am help, dechreuodd Rhys ddeall ei sefyllfa.

At the earliest opportunity, as everyone decided to return to search for help, Rhys began to understand his situation.

Roedd yn sownd, a doedd y storm ddim yn helpu i leddfu'r teimlad o fod ar ei ben ei hun yn y dwnjan dywyll.

He was alone, and the storm wasn't helping to dispel the feeling of being alone in the dark dungeon.

Roedd oriau yn pasio, a thybiai Rhys fod pawb wedi gadael y castell.

Hours passed, and Rhys thought everyone had left the castle.

Yn sydyn, clywodd gamre o'r tu allan i'r drws.

Suddenly, he heard a noise from outside the door.

Nid oedd yn gadael i'r cyfle hwn fynd heibio; dechreuodd wneud swn mor fawr â phosibl, gan guro ar y drws a gweiddi.

He wasn't going to let this opportunity pass; he began to make as much noise as possible, banging on the door and shouting.

I'r ymwelwyr oedd dal i edrych o gwmpas y castell, swniodd hyn fel ysbryd go iawn!

To the visitors still looking around the castle, this sounded like a real ghost!

Criau eu hofn a'u dychryn yn atseinio trwy goridorau'r castell.

Their screams and fright echoed through the castle corridors.

Yn fuan iawn, daeth gweithiwr y castell i achub Rhys yn olaf, a darganfod ei fod yn ddiogel.

Very soon, a castle worker came to rescue Rhys at last, finding him safe.

Gwen a Evan oedd y ffodusaf oll i glywed ei fod yn iawn.

Gwen and Evan were the luckiest to hear that he was okay.

Roedd hyn yn achosi chwerthin mawr a rhoi rhyddhad iddynt, gan sylweddoli fod 'ysbryd' y dwnjan dim ond Rhys ar goll!

This caused great laughter and relief for them, realizing that the 'spirit' of the dungeon was just Rhys lost!

Dychwelodd pawb adref gyda stori ysbryd go iawn i'w hadrodd, sef yr amser y bu farw'r hanes a'r chwedlau'n fyw am noson ryfeddol a digyffro yng Nghastell Caerffili.

Everyone returned home with a real ghost story to tell, the time that the history and legends came alive on a strange and thrilling night at Caerphilly Castle.

Ac roedd Rhys yn sicr na fyddai'n gadael hanner golwg oddi ar y llwybr ar daith arall eto!

And Rhys was certainly not going to leave the halfway point of the path on another tour again!