The refurbished swimming pool at St Piran's School was opened on Wednesday by a top swimmer.
Former pupil, Fabian Whitbread, opened the pool and took a dip in the water.
Headteacher Jonathan Carroll, said: "It really is a great facility, not just for our children but for all sorts of people and groups."
The six-figure revamp for the pool is one of three recent makeovers the school has undertaken in the last year.
Earlier this year the reception pupils moved into a new block and in the summer term the school reopened their all weather pitch.
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