:List of SSSIs in West Gwynedd
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Lists of Sites of Special Scientific Interest in West Gwynedd (1974–1996) comprise:
- List of Sites of Special Scientific Interest in Anglesey
- List of Sites of Special Scientific Interest in Gwynedd
{{Protected areas of Wales|state=collapsed}}
{{list of lists| geography |listcat=Lists of Sites of Special Scientific Interest|sort=West Gwynedd}}