The sites are marked with a blue triangle on an orange background, the international civil defence symbol, alongside a green sign bearing the words Punkt schronienia (shelter area).
They are places offering temporary, basic protection from strong winds, storms or shrapnel. Examples include underground car parks, tunnels and underground parts of buildings.
The sites are listed on the State Fire Service's free online map, Gdzie się ukryć (Where to Hide).
Building owners and managers are responsible for marking the sites and have until December 31 to do so.
The city said locations in municipal buildings would be marked gradually by the end of the year.
Officials stressed that a designated shelter area does not offer the same level of protection as a purpose-built shelter.
The city is checking the condition of around 300 older structures, preparing temporary shelter locations and planning new shelters.
One new structure is planned for Hubska Street and is expected to accommodate around 500 people.
Polish state news agency PAP reported in early October that none of Wrocław's approximately 300 known historic shelters currently met the requirements for civilian protection.
By mid-August, 223 inspections had been commissioned, and complete documentation had been prepared for 180 sites for building supervision authorities and the fire service.
A further 36 sites had been identified as potential temporary shelter locations.
Tomasz Sikora, deputy director of Wrocław City Hall's social communication department, told PAP in October that the main challenges were the scale of the city's needs and the condition of its existing infrastructure.
According to city estimates, even adapting all 300 older protective structures would meet only around 5 percent of the city's needs.
Many have had their air-filtration and ventilation equipment removed, their installations are not working, and their rooms are not airtight.
(sp/gs)
Source: PAP