Work has begun on a trench around a park in Brighton which has been used as a traveller encampment several times.
Withdean Park has been used by travellers four times this year.
Following complaints from residents, Brighton and Hove City Council is putting a ditch and embankment along the road to stop vehicles driving on to the site.
The council has also launched a search for a new permanent travellers' site.
The bank will run along the front of Withdean Park, on the A23, and will be approximately 330ft (100m) long, with a combined width of 8ft (2.5m).
Green Party councillor Pete West, who is the cabinet member for the environment and sustainability, said: "The number of encampments travellers have used traditionally have been lost over the years.
"It's driving them into the city and using parks more and more, which is not acceptable for the local population - we're looking to take a firm stand on that.
"We're also looking for a permanent site for travellers to go along with our transit site, because we have to be fair to the travellers that do live in this area and want to come to this area."
The council hopes the ditch and bank will not be too visible from the road and will blend into the natural slope of the site where possible.
A council spokesman added: "We are choosing the method as in the longer term it will merge into the surroundings, other defences such as posts and fences also have a limited lifespan."
Similar works can be seen at Waterhall Playing Fields and Hollingbury Park.