After a conference dominated by the growing political crisis over Brexit, Plaid Cymru activists joined a cross-party protest against Brexit.
The demonstration in Bangor heard calls for a 'people's vote' referendum on whether to leave the European Union after all.
It comes as a reported one million people marched in London demanding a second Brexit vote, and an online petition calling for Brexit to be cancelled approached 5 million signatures.
Earlier, Plaid Cymru’s Westminster leader, Liz Saville Roberts told ITV Wales news that the UK government is trying to reach out to other parties to find a way out of the Brexit deadlock.
She said that Theresa May's deputy, David Lidington, had spoken to her on Friday about her party's attitude to so-called 'indicative votes', to see if there was a policy that a majority of MPs would support.
But Ms Saville Roberts doubted that the Prime Minister could stay in office much longer.