The Castle Pond link will be closed on its North side from the end of the month while new railings are installed by Pembrokeshire County Council.
Work is due to start on 29th January for 21 days initially. The route is due to be closed for the safety of the public from the South end of the barrage to the Rocky Park entrance and the Corn Store whilst works are in progress.
The quayside opposite Pembroke Castle will remain open for businesses to continue as normal.
Cabinet Member for Planning and Housing Delivery and Local Member Cllr Jon Harvey said: “It’s great to see these railings being installed but we are aware that this is a popular and heavily used route so the closure will cause some disruption.
“We believe that the closure for safety will be worth it once the new railings are installed for the benefit of all users and we thank residents for their patience.”