Grosnez Castle

Has been described as a Certain Masonry Castle

There are masonry ruins/remnants remains

NameGrosnez Castle
Alternative Names
Historic CountryJersey
Modern AuthorityJersey
1974 AuthorityA
Civil ParishSt Ouen

On the cliffs at Les Landes, at the most north-westerly point of Jersey you can find the ruins of Grosnez castle, built between 1328 and 1330. Little is known about the history of this roughly built fort. Grosnez- meaning either 'big nose' in modern day Jersey/French Patois or "great headland" (from the Norse word 'ness') - was built to protect the islanders from the French. It was obviously not intended to withstand a siege as water would have to be carried from the nearest spring, 200 yards away. Additionally, there were no secondary walls inside the castle so once the outer walls were breached it's capture was certain. The castle was captured in 1468 and by 1540 it lay in ruins, local legend has it that much of the stone was used to build St. Ouen's Manor. What is known is that locals took down the castle deliberately and used the stones on their own land particulary around the Mont Mado area of St. John from where the stone originally came. What remains today is a gatehouse separated from the mainland by a big ditch and a section of wall. (

Popular refuge. Promontory site, defended by lofty cliffs, irregular ward with round towers and a square gatehouse; inner buildings consisted only of small hutments. Probably built c. 1328 (King 1983)

The understanding of the site and its history is limited due to the lack of any recent documentary or archaeological research. Research into the castle's history was carried out as far back as 1897 (Le Cornu) and more recently in 1926 (Rybot). The archaeology, both structural and below ground, holds a great deal of evidence. Grosnez Castle is a fortified stronghold thought to have been built around 1330 on the orders of the Warden of the Isles, Sir John des Roches, to serve as a refuge from French attack for islanders in this part of Jersey

The 14th century was the period of the Hundred Years' War, when the French were making constant tip-and-run raids on the Island. The castle was twice captured by the French, in 1373 and 1381. The castle is said to have been captured by a French force led by the Duke of Bourbon in July 1373 in conjunction with an attack on Mont Orgueil by Bertrand du Guesclin. In the account of du Guesclin's raid in 1373 the Duke of Bourbon's standard-bearer reports: "We arrived in Jersey, where there are two castles. The Duke and his men set themselves in array against one and the Constable and his men against the other." It was captured again in 1381, and is thought to become a ruin around the time of the French occupation of Jersey (1461-1468). Local tradition has it that much of the stone was used to enlarge St Ouen's Manor around 1483, and that locals also took down the castle deliberately and used the stones on their own land. It is unlikely the seigneur of St Ouen would have been given such permission if the castle was still in use. On Leland's map of the Channel Islands, published about 1540, it is marked as Grosnes Castrum, dirutum (Grosnez Castle, destroyed). In 1607 the Attorney-General challenged the right of the seigneur of St Ouen to hold his feudal court there, on the grounds that all castles belong to the king; but the Commissioners ruled that, as it was "but a heap of rubbysh and stones", the seigneur might be left in possession.

A ruined fortified circular stone enclosure with a gatehouse, curtain walls and rock cut ditch, with traces of simple buildings to the interior. The granite curtain wall is about 250 metres long and encloses an area roughly circular in shape. The walls are thickest on the landward (S) side - the other sides (N, E & W) being protected by natural steep cliffs some 60 metres high. The most substantial standing structure is the gatehouse, which was protected by a drawbridge and portcullis. There is a portcullis groove descending to passage level, and below the groove is a pit for a counterpoise type drawbridge. Flanking the gatehouse are two D-shaped towers (now reduced to about 2m high). The west tower has remains of two arrow slits at ground level. Between the gatehouse and the east tower is a ramp up to the former wall-walk. There are two other towers further around on the east and west sides, but beyond them the natural defences presumably made flanking towers uneccesary. In front of the gatehouse is a broad ditch cut through the solid rock, originally crossed by the drawbridge. Archaeological excavations of the ditch revealed 12 carved corbels from the gatehouse (now on display at La Hougue Bie Museum). Inside the walls can be traced the foundations of groups of modest structures. (State of Jersey HER)

This site is a scheduled monument protected by law

Not Listed

Historic England (PastScape) Defra or Monument number(s)
County Historic Environment Record
OS Map Grid Reference
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Copyright Wayne Barr and licensed for reuse under this Creative Commons license.
Copyright Wayne Barr and licensed for reuse under this Creative Commons license.
Copyright Wayne Barr and licensed for reuse under this Creative Commons license.

Most of the sites or buildings recorded in this web site are NOT open to the public and permission to visit a site must always be sought from the landowner or tenant.

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  • Salter, Mike, 2001, Castles and Old Churches of the Channel Islands (Malvern; Folly Publications) p. 42-3
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 2 p. 543


  • Toulmin-Smith, Lucy (ed), 1909, The itinerary of John Leland in or about the years 1535-1543 (London: Bell and Sons) Vol. 4 p. 187 online copy


  • Clark, Kate, 2008, Valuing the Heritage of the Channel Islands (Kate Clark Associates for Jersey Heritage) online copy

Guide Books

  • Jersey