Stretching from the tip of the Fremantle Town Hall clocktower to the foot of the Roundhouse, odd scraps of yellow have been appearing on the historic buildings of High Street.

The pieces appear jagged, random and become denser towards the Roundhouse — Western Australia's first convict-built prison.

Climb the Roundhouse stairs and the image suddenly snaps into focus.

The full artwork can be seen from the stairs over the tunnel at the Roundhouse. ( ABC Radio Perth: Emma Wynne )

Six large yellow ellipses that appear flat against the three-dimensional landscape rise up over the street.

Arcs d'Éllipses is the work of Paris-based Swiss artist Felice Varini, who has produced geometric optical illusions around the world.

His previous canvasses have included the Louvre in Paris, the Palace of Versailles and an entire village in the Swiss Alps.

This latest work on High Street has been created for High Tide, the inaugural Fremantle art biennale.

Artist Felice Varini oversees the final piece of Arcs d'Éllipses going into place. ( ABC Radio Perth: Emma Wynne )

"I'm doing a pictorial work that takes into account the architectural configurations and details in this entire street and I play, a bit like in an arena, and interact and engage with High Street," Varini said.

The outlines for the Fremantle piece were created over four nights when High Street was plunged into total darkness, then a large projector lit up the design on the buildings.

A small army of assistants climbed and used cherry pickers to create the precise outline.

After that, the team spent three weeks filling in the outline with yellow colour.

Over 2,500 painted strips of thin, adhesive aluminium were used. ( ABC Radio Perth: Emma Wynne )

"The colour is in fact very thin aluminium sheets, which are self-adhesive," Varini said.

"Because the artwork is of a temporary nature, the work has to be removeable and this is the material we have developed over time that best fits."

Although the installation only completely makes sense when viewed from the Roundhouse stairs, Varini wants the public to enjoy the splashes of colour and be intrigued as they walk down the street.

Felice Varini wants the work to be enjoyed from all angles — not just the Roundhouse stairs. ( ABC Radio Perth: Emma Wynne )

"All these fragments and the different perspectives are just as important as the actual 'so-called' point of view where the illusion happens," he said.

"I am not limiting myself to one perspective but a whole range of different perspectives."

The last of several thousand fragments was stuck into place on Tuesday, on the roof of the Navy Club of Fremantle.

The work is made from sticky aluminium strips that will not damage the building facades. ( ABC Radio Perth: Emma Wynne )

Arcs d'Éllipses officially opens on Saturday October 28 but has already garnered an enthusiastic response from visitors to the street.

"So far there has been a lot of positive feedback and comments, people congratulating me and thanking me for coming all the way to Fremantle to realise this work," Varini said.

Arcs d'Éllipses will remain in place until December 30.