Timed to coincide with the Yours & Owls music festival, which will take over Stuart Park on the long weekend, the Wonderwalls festival will once again transform Wollongong's city walls into an art gallery.

Festival organiser and Verb Syndicate founder Simon Grant said there were big things planned for the third Wonderwalls festival.

"We've got local national and international street artists scheduled, no one that we can name just yet," he said.

"There's a heap of walls, some that will be intertwining with [Wonderwalls] spots that already exist, and then we've got some new spots.

"They're all within walking distance of the mall."

"We're also going to try to do some crossover stuff, we've got a few little things planned between our festival and [the Yours & Owls] festival."

The two-year break for the popular Wollongong festival was due to an opportunity that arose in Port Adelaide this January, when festival organisers arranged for a nine-story mural to be painted on the side of the town's old Fisheries building.

"It's a huge amount of work to pull together a festival, to get the walls and the artists to come together," Mr Grant said.

"We've got some good support from Wollongong City Council and Destination Wollongong, but it's not our full-time job. So we didn't want to try to do a festival in 2014 and then one at the start of this year in Adelaide too."

In 2013, renowned mural artist Smug transformed the beige concrete of Myer's Burelli Street frontage into a lifelike portrait of a man and koala that spans two storeys.

Some of the other notable works from previous years include the striking portrait of a woman by Melbourne street artist Rone, which adorns the Dion's building in Keira Street, and the colourful murals which can be seen in some of the lesser known laneways, like Court Lane or Moores Lane.

Mr Grant said there were plans to highlight under-used laneways.