An investigation into the deterioration of historic buildings in the St Mary's Hospital campus in Dublin's Phoenix Park has been launched by Dublin City Council.
The Health Service Executive has posted warning notices on buildings at the site which was originally the Royal Hibernian Military School built in the 18th Century.
The city council's Conservation Officer is investigating as the original buildings are protected structures.
"Owners or occupiers of Protected Structures are legally required to make sure that the structure does not become endangered through neglect, decay, damage or harm," the council said in a statement.
There are also modern buildings in the campus which houses 150 nursing home beds, and a separate 48-bed step-down hospital for older people.
The HSE ordered a review into the running of St Mary's after there was a protected disclosure and 24 Covid-related deaths at the facility.
In a statement, the HSE said that cottages and flats to the front of the campus have been fenced off to prevent unauthorised access into the buildings that have "fallen into disrepair".
It said that a number of housing bodies had turned down an offer to take the buildings because of the state of the structures, their size and the poor access to them.
"The HSE have not been in a position to progress this issue any further during the Covid-19 emergency response but will recommence efforts to establish a suitable use for the buildings once Covid 19 emergency response has passed," the statement added.
The Royal Hibernian Military School was established in 1769 by the Hibernian Society, a philanthropic organisation founded in Dublin after the Seven Years War between England and France to help children orphaned by the deaths of soldiers.
It later included the sons of soldiers serving overseas and there were additions to the original building during the 19th Century.
The school and its pupils were transferred to England following independence and the Irish Army took over the buildings as a military hospital.
It became a "chest hospital" in 1948 and finally in 1964 became a facility for older people.
The protected structures include the central building with two wings and connecting buildings, a gate lodge, mortuary chapel, Church of Ireland chapel and cemetery and walled garden, former farm buildings and the cenotaph.
