A European flag etched into a paving slab on Colwyn Bay promenade has sparked accusations of EU propaganda.
The slab, part of the Waterfront Project which is part-funded by EU cash, was spotted by a Conservative town councillor.
UKIP MEP Nathan Gill said it was "insensitive" of Conwy to set into concrete the EU flag.
Conwy council said it was obliged by the terms of the grant to acknowledge the source of the funding.
The UK is due to leave the European Union in March 2019, following the 2016 referendum when a majority of those voting in Wales backed Brexit.
The slab is part of phase two of Conwy council's Waterfront Project, which includes coastal defence work and environmental improvements.
The £4.5m scheme is supported by Welsh Government and £1.6m of EU funds.
Mr Gill, who is also an independent AM for North Wales, said: "I understand that until we leave the EU in May 2019 it is still 'technically' business as usual - we still pay into the pot and get some of our money back.
"But I think this is very insensitive and short-sighted of Conwy council to set into concrete the EU flag, with the date 2017, a year after Wales and specifically Conwy voted to leave.
"This flag will be embedded on our sea front for decades after we have left, and made a huge success of Brexit."
Adrian Mason, a Conservative town councillor in Colwyn Bay, said: "I'm disappointed on the basis that it is EU propaganda.
"Why they choose to do that now, while we are leaving, is beyond me."
A Conwy council spokeswoman said that in accepting EU funds for the project, which was approved prior to the referendum, it had an obligation to acknowledge it was part-financed by the European Regional Development Fund.
Remain-supporting Llyr Gruffydd, Plaid Cymru AM for North Wales, said: "Regardless of whoever paid for it, it's only fair that people that provide funding are recognised."
He added: "It may remind many people of what we potentially might lose when we leave the EU."