Portsmouth City Council' s planning committee approved a redesign of the planned new flood defences on Wednesday saying it better reflected the history of the area while also contributing to 'a world class seafront'.
The council approved the £131 million flood defences programme in December 2019 covering a three-mile stretch of the coast.
Work started at Long Curtain Moat last year and is expected to be completed in 2026.
But new plans were lodged earlier this year, seeking approval for a redesign of the section at Southsea Castle.
These were backed by Historic England before the application went before the council's planning committee on Wednesday for a decision.
Speaking at the meeting, councillor Robert New said the new promenade would contribute to a 'world class seafront' while also providing a key part of the new flood defences.
His comments were echoed by the committee's chairman, councillor Lee Hunt.
'Over the last 30 years or so, the seafront has changed enormously from what it used to be and for the better,' he said.
'This is one of the most important heritage sites in the UK and there's no question that this variation better reflects that.
'It improves it from the proposition we had before: It's less rock, it's less piling, it's less interruption under the water and it's going to be a great place where people will want to come and sit on the steps and look out to sea.'
The application was then approved unanimously by the committee.