Like they undoubtedly did back in the places like Pompeii more than 2000 years ago and even 30,000 years back in what was known as the Upper Paleothic times.
Startling murals have been uncovered on the walls of great caves in southern France, so it's fair to say then that creating large paintings is certainly nothing new.
It's just that they have become more creative as the minds of the artists go to work to deliver something you will stop and look at.
In the wake of the original 29 being finished, I saw for myself the effect they had, with tourists (and I daresay some locals) stopping to photograph them.
They went up on great walls within the CBD and across the outskirts - all generally in pretty close proximity to the inspiration for them which is the sea.
I think the concept is inspired, and I think the results we saw from that first round when the brushes and paints came out were exceptional.
And I'm confident in predicting that the 20 new murals now under way will be equally exceptional, given the skills of the artists involved.
It has brought international mural artists into the city as well as five local artists, and they will all be delighted to be not only given fine canvases to cover but good weather to go with it.
While I can wield a drawing pencil reasonably well I am always in awe of the scale of these works and often stop to watch them evolving.
My response does not alter.
"How do they do that?"
Fine slices of ecological colour and culture, and a real spark for the city land (and sea) scape.