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Countryside Council for Wales
Landscape & wildlife Please note - A new body, Natural Resources Wales has taken over all functions and services previously carried out by Countryside Council for Wales. While the Natural Resources Wales website continues to be developed, some online services will continue to be provided on this web site.

Sully Island

The excellent sea-cliff exposures of Sully Island provide an insight into the environment of the area in Triassic times, approximately 200 million years ago. Red mudstones, sandstones and breccias (rocks made from angular pebbles) indicate that this area was a beach situated on the margin between steep semi-desert land and a large shallow lake or marine lagoon. These Triassic rocks were deposited on top of much older Carboniferous limestone which can be seen at the base of the cliffs. Sully Island additionally provides a roost site for waders feeding in winter in the local area.

Sully Island SSSI aerial photo

© This orthophotography has been produced by COWI A/S from digital photography captured by them in 2006. Licensed by the Welsh Assembly Government's Department for Environment, Planning and Countryside.

Managing this site

The site is in private ownership. The special features of this SSSI and CCW’s views about site management have been summarised in a Site Management Statement, addressed to the owners and managers of the land. The statement can be found in the resource section below.

Access information

There is no public access to this site.

Other information

Sully Island is situated opposite the eastern extremity of the parish, offshore, and joined to the mainland at low tide by a causeway. Sully : Sili means ‘place associated with (de) Sully’. Sully is a personal name. The origin of the name is obscure. The de Sully family held the manor from the last decade of the 12 cent. but it is difficult to establish whether they derived their name from the place, or whether the place was named after them. It has been suggested that the name was transferred directly from Sully or Silly in Normandy.




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Email address
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The landscapes team [SSSI]
C/O Enquiries
LL57 2DW
Telephone number
0845 1306229
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