
Holyhead High School is setting out plans to move to a new building in the next five years.
Anglesey Council says the discovery of RAAC concrete in September 2023 at the current site on South Stack Road had a huge effect on pupil education.
It also faces signficiant maintenance costs.
Next week, council chiefs will consider plans for a public consultation on a new site near the town's leisure centre, which could open as early as September 2030.
Aaron C Evans, director of education at Anglesey Council, said: "Officers have considered a number of different options for the provision of secondary education in the Holyhead area."
“We’ve come to the conclusion that a new building for Ysgol Uwchradd Caergybi is the best way forward. Creating a new modern building would be a significant investment in education in Holyhead and Holy Island and would also ensure the long-term sustainability of secondary education in the area.”
“It would also be a big step towards providing the best possible educational standards and increasing the use of the Welsh language as well as achieving the aims of the county council’s Modernising Learning Communities and Welsh Language strategy.”
The council says the new building would need specialist modern learning facilities "of the highest standard" and more open, green spaces - along with enough secondary school places to meet the needs of 11-18 year olds both now and in the future.
The consultation proposals will go before the council's corporate scrutiny committee on Wednesday before the executive make a decision on Thursday.
If it's approved, a public consultation on a new building for Holyhead High School will take place in June - but ultimately, the new school would be dependent on securing Welsh Government funding.