The largest lowland fen in Wales

This site might be described as a miraculous survivor, something well appreciated on any visit as you pass the entrance to a major recycling plant, and, on reaching the higher ground see no distance away, an oil refinery, industrial area and docks.

Forget these for a few minutes and visualise how the Bog would have looked in far off times, indeed, an inlet of the sea some three miles long until about 800 years ago when a violent sandstorm blocked the entrance and the Bog began to form. The Tennant Canal along the southern boundary was the brainchild of George Tennant, who, in 1819, linked the rivers Neath and Tawe, the last traffic being in 1934. The towpath provides tranquil access between Pant Sais Fen and the considerably larger Crymlyn Bog, together comprising the National Nature Reserve some 663 acres in extent.

Despite its size, Crymlyn Bog was largely overlooked by naturalists because of its urban and industrial location and could have been lost until Andrew Lees, having recognised its importance, commenced a campaign to prevent an extension of the landfill site. A successful campaign eventually resulted in designation as a National Nature Reserve and in 1993 as a Ramsar Site, while Pant Sais Fen was compulsorily purchased by the local council. Here you will find a memorial to Andrew, who tragically died in 1994, the quotation his own words: “At some point I had to stand up and be counted. Who speaks for the butterflies?”

Crymlyn with its vast reedbeds sadly lacks an extensive area of open water. Why no boardwalk culminating at a lagoon, a lagoon with shallow feeding areas and small islands?