A huge ring-shaped walkway designed by architect George King is set to be built next to Flint Castle in Wales – but has been met with fierce opposition by locals, who see it as symbol of historic oppression.

George King Architects, which has offices in London and Gloucestershire, was awarded the project following a nation-wide competition that invited leading artists and architects to present ideas for a site near the castle in north Wales.

However local residents see the project as a reminder of how Edward I, King of England from 1272 to 1307, tried to "subjugate and oppress" the Welsh people – and have launched a petition calling for the design to be scrapped.

"We find this extremely disrespectful to the people of Wales and our ancestors who have battled oppression, subjugation and injustice for hundreds of years," reads the petition, which is just short of its target of 9,000 signatures.

Flint Castle is situated beside the River Dee and was begun in 1277. It was one of the first castles to be built in Wales by Edward I, who went on to construct further castles in the region forming an "Iron Ring" used to suppress Welsh resistance.

King's design is intended to represent this ring. According to the architect, it "symbolises a giant rusted crown representing the relationship between the medieval monarchies of Europe and the castles they built."

Set to cantilever from the earth to a height of seven metres, the 30-metre-diameter structure will incorporate a walkway offering elevated views across the estuary of the River Dee and towards the castle.

"The sculpture will take a precariously balanced form, half buried beneath the ground, half projecting into the air, to demonstrate the unstable nature of the crown," said King.

"The sculpture has been carefully designed to work at many scales. From afar its striking, iconic form resembles a giant ancient artefact, washed up on the shore of the Dee Estuary."

The weathering steel structure will touch the ground at just two points. There are also plans to engrave its inner surfaces with words and phrases chosen by local residents to celebrate landmarks, historic towns and flora and fauna from the surrounding area.

The design was selected by a panel of experts from the Welsh Government's historic environment service (Cadw) and Arts Council for Wales, which was looking for an artwork celebrating Wales' Year of Legends.

The £395,000 installation is scheduled to open in 2018, as part of a wider masterplan to regenerate the area around the castle and the Flint Foreshore.

The castle itself will be enhanced through the introduction of a stainless-steel spiral staircase costing £217,000, which will be inserted into the space once occupied by the original masonry stairs and will provide visitors with access to a new viewing platform in the tower.

George King Architects regularly works on commissions for interactive installations, sculptures and small artworks, including a glowing maze-like installation in Detroit created using ultra-violet wool thread.