The Société Jersiaise is appealing for information after Dolmen de Mont Ubé was daubed in spray paint.
The Neolithic passage grave was built around 6,000 years ago and can be found in trees around 100 metres from Rue de la Blinerie.
Writing on its Facebook page, the Société asked anyone with information about the vandalism to get in touch.
In a post alongside pictures of the graffiti, the organisation says: ‘It’s a shame somebody has felt the need to deface the beautiful Mont Ubé Dolmen.
‘If anybody has any information please contact us through our Facebook page or by emailing info@societe-jersiaise.org.’
The post has been shared hundreds of times and some Islanders have offered to help clean off the paint.
