Noticeboards have been put up in the area, showing a diversion route for promenade users over the closure period and previewing the completed design.
Cllr Hugh Mason, cabinet member for planning policy and city development said: ‘We decided to wait until January to close this section of promenade so that people can have full access over the Christmas and New Year periods.
‘By creating a diversion route we are ensuring that people can still use the area around the landward side to the castle while we replace the current promenade and build the new sea defences.
‘Once reopened, a new split-level promenade will improve accessibility and create a sense of openness around Southsea Castle and along the seafront.’
The Southsea Coastal Scheme is the UK’s largest local authority-led coastal defences’ project, worth more than £100M. It will stretch for 4.5km from Old Portsmouth to Eastney. Work is currently going on at the Old Portsmouth end of the seafront, up to Clarence Pier.