Water drains from high ground above the village of Crymych in Pembrokeshire, and at one time flowed at ground level across the main Cardigan–Tenby road (A478) before falling to the level of the defunct Whitland and Cardigan Branch Line railway station "Crymmych Arms" (Great Western Railway) where, on the UK Ordnance Survey map of 1866 it is shown as the source of the Taf.
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To the south of the estuary are the great flat sands of Cefn Sidan and Pembrey, whilst across the estuary on the banks of the River Taf is Laugharne famed for its association with Dylan Thomas.