THE Cleddau river has more than its fair share of history, and in next week's 'Rivers of Wales' (Thursday, October 18, BBC Two Wales) BBC Wales Today presenter Sara Edwards uncovers some religious ructions on the riverbank.

Following the Eastern Cleddau across the Preseli Mountains, Sara comes across a small chapel at Rhydwilym. At one time, a draconian Act of Uniformity forbade church services in Welsh, but local people knew how to get around it by taking advantage of the Cleddau's county boundaries.

"Pembrokeshire and Carmarthenshire lie on either side of the river, and the tiny congregation would assemble on the river-bank for their service," explained Sara.

"Boys would be stationed in the lanes as lookouts. If a constable was spotted on the Pembrokeshire side then the whole congregation would wade across the river into Carmarthenshire and continue the service because the constable had no powers in another county, and it worked in reverse if a Carmarthenshire constable was approaching. But history doesn't tell us what might have happened if both constables approached the river at the same time."

Passing one of the best preserved stone rings in Wales, the Gors Fawr Stone Circle, the Cleddau continues its journey to the sea. At Llawhaden, Sara finds a castle overlooking a church built right next to the river. It was once the scene of holy fisticuffs between two Welsh saints - Aiden and Gwyndaf.

"They fought over who should build the church next to the river," said Sara. "But the fight wasn't over religious belief or who was the more devout Christian - it was over fishing, because they both wanted to own the rights."

Sara is joined by GMTV anchorwoman Fiona Phillips, who tries her hand at fishing for the first time on the Cleddau, near her parents' home in Haverfordwest. She also meets up with Lord Parry of Neyland to find out more about Neyland Bridge at Milford Haven Estuary, and talks to geologist John Davies about the wealth of history of the Cleddau, the geology of the river and its journey to the sea at Milford Haven.

'Rivers of Wales' can be seen on BBC Two Wales on Thursday, October 18, at 7.30 pm.