Repair and maintenance work has started on Southsea Castle after Portsmouth City Council committed over £200,000 worth of capital funding.
The work, which started this week, includes essential repairs to the external parapet walls and electrical works to the Eastern Bastion, including the installation of new lighting.
The work has been timed to minimise disruption to planned events during the summer season. While the castle will remain open throughout the work there may be reduced access to some areas at times which will be agreed with the occupants to limit disruption.
The first phase of work is likely to be completed by the end of May 2018 with a second phase planned for March - May 2019.
Councillor Frank Jonas, Portsmouth City Council's Cabinet Member for Resources, said: "Southsea Castle was built in 1544 and is one of the city's most loved historical attractions. It is important that we continue to invest in its repair and maintenance so it can be enjoyed by residents and visitors from around the world for many years to come."
The money is part of the council's capital budget which invests in a range of infrastructure schemes throughout the city like buildings and facilities, rather than the day-to-day running of council services that have to be paid through a separate revenue budget.