Travellers moved from Waterhall Golf Course appeared in Surrenden Park, Brighton, this morning.
A group of 11 caravans turned up at about 9am.
Terry Purcell posted this picture on Twitter earlier today.
The gate to the field was wide open, though the council says it was secured overnight.
Brighton and Hove City Council has confirmed the unauthorised encampment and has visited the site with the police to carry out a community impact assessment.
A spokeswoman for Brighton and Hove City Council said: "There was damage to the gate, so looks like a break in.
"The council’s traveller team has visited the site and is in discussion with the police on next steps."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article