Sarn Badrig

Shingle reef in Cardigan Bay, Wales

Sarn Badrig 4 km from land
Visible at very low spring tide

Sarn Badrig, also spelled Sarn Padrig (Welsh for 'St. Patrick's causeway'), is one of several more or less parallel shingle reefs extending under the sea in Cardigan Bay on the west coast of Wales. The causeway is made of glacial deposits left by receding ice sheets at the end of the last ice age.

Sarn Badrig is the longest and most northerly of these, and extends south-westwards under the sea from Mochras Point, near Harlech, parallel to the Llŷn Peninsula for a length of about 20 km, and can be seen at low tide. It is a hazard to shipping.

A neighbouring causeway is that of Sarn y Bwch, which is close to Tywyn.

Another example can be found at Sarn Gynfelyn, which is north of Aberystwyth.

In Welsh legend it is one of the dykes which protected the drowned realm of Cantre'r Gwaelod.

Points of interest

Point Coordinates
(Links to map resources)
OS Grid Ref Notes
Bell buoy marking western hazard 52°41′11″N 4°25′21″W / 52.68631°N 4.4225°W / 52.68631; -4.4225 (Bell buoy marking western hazard) SH36271263
-5m depth western point 52°41′28″N 4°21′46″W / 52.69112°N 4.36283°W / 52.69112; -4.36283 (-5m depth western point) SH40321303 approx (from marine chart)
0m depth western point 52°42′11″N 4°20′18″W / 52.70307°N 4.33841°W / 52.70307; -4.33841 (0m depth western point) SH42021431 approx
Mid point of visible sarn 52°44′26″N 4°14′35″W / 52.74054°N 4.24303°W / 52.74054; -4.24303 (Mid point of visible sarn) SH48591827 approx
Eastern point of visible sarn 52°46′54″N 4°09′40″W / 52.78167°N 4.16098°W / 52.78167; -4.16098 (Eastern point of visible sarn) SH54262268 approx
Landing at eastern end 52°48′29″N 4°09′05″W / 52.80812°N 4.15148°W / 52.80812; -4.15148 (Landing at eastern end) SH54992560 approx

External links

Map all coordinates using OpenStreetMap

Download coordinates as:

  • KML
  • GPX (all coordinates)
  • GPX (primary coordinates)
  • GPX (secondary coordinates)
  • Cantre'r Gwaelod (The Lowland Hundred)
  • Sarn Badrig - St. Patrick's Causeway
  • www.geograph.co.uk : photos of Sarn Badrig

52°44′26″N 4°14′35″W / 52.7405°N 4.2430°W / 52.7405; -4.2430


  • v
  • t
  • e