Under Salt Marsh (often shortened to Salt Marsh) is filmed across several real locations in north and west Wales, with the fictional town of Morfa Halen created from a blend of these places.

Main filming locations

  • Barmouth, Gwynedd – This seaside town and the Mawddach Estuary provide the primary backdrop for Morfa Halen, including many seafront and town scenes.
  • Fairbourne, near Barmouth – The salt marsh and coastal village shots, including promenades and residential streets, were largely filmed in Fairbourne.
  • Shell Island / Llanbedr – Used for the causeway and marshland vibe that inspired the idea of a town at the end of a tidal route across the salt marshes.
  • Anglesey (Ynys Môn) – Key locations include Newborough Forest, Aberffraw, Malltraeth, and Menai Bridge, which provide dunes, coastline, and village scenery for Morfa Halen.
  • Cardiff (studio and set work) – Some marsh and town elements, especially complex marsh sequences, were built and shot around Cardiff.

So, if you’re asking “where is Salt Marsh filmed?”, the answer is: it’s mainly shot around Barmouth and Fairbourne in north‑west Wales , with additional scenes in Anglesey, Llanbedr/Shell Island, and Cardiff standing in for the fictional town of Morfa Halen.

TL;DR:
Salt Marsh’s fictional town, Morfa Halen, is not a real place – it’s stitched together from real Welsh locations like Barmouth, Fairbourne, Shell Island/Llanbedr, Newborough Forest and villages on Anglesey, plus some work in Cardiff.

Information gathered from public forums or data available on the internet and portrayed here.