The latest exhibition at the Art Gallery of Western Australia has seen the state collection raided to highlight the first impressions of the colonists.

Unknown Land: Mapping and Imagining Western Australia opens on Saturday and comprises works created by people who arrived in the Swan River colony after it was founded in 1829.

"It's very much about how Europeans, when they encountered Western Australia, actually made sense of this new land in a visual sense," curator Melissa Harpley said.

Melissa Harpley says the exhibition is a chance to see Perth through the eyes of the first colonists. ( 720 ABC Perth: Emma Wynne )

"Obviously the land wasn't unknown to the Aboriginal people who lived here for thousands of years.

"These pictures were made as a record, sometimes for themselves and sometimes to send back to friends in the UK."

The items featured in the exhibition range from professional artists, trained draftsmen from the military, as well as amateurs who simply wanted to make a record of their new home.

"I'm also amazed at the sheer volume of works that were actually made," Ms Harpley said.

"There were a lot of people out here busily drawing and making watercolours."

Before the freeway and the narrows bridge: Mount Eliza in 1827 by Frederick Garling. ( Supplied: Art Gallery of Western Australia )

The works provide a rare look at what Perth city, Mount Eliza, Fremantle and towns in the south-west looked like before any development.

Ms Harpley said they were also revealing for what they do not show.

"They certainly leave out the history of conflict with Aboriginal people that was prevalent in the Swan River area then.

"They also glide over scenes of hardship, the fact that quite often crops weren't as productive as hoped.

"It's a fairly rosy image."

A watercolour of the Fremantle foreshore, painted by an unknown artist circa 1869. ( Supplied: Art Gallery of Western Australia )

While a few pieces are on loan, the bulk of the works come from the state collection.

"We have rich holdings of this colonial material," Ms Harpley said.

"For me, one of the astounding and fabulous things is the strength of our collection that we have been able to put on the walls.

"I hope that audiences engage with the images and look closely at them.

"In a clichéd way, it's about learning from the past to think about the present."

Unknown Land will be at the Art Gallery of Western Australia until January 30.