These form part of the union's three-month civil service-wide campaign against imposed cuts to pay, pensions, jobs and working conditions, which has involved weeks of rolling industrial action among the union's 250,000 public sector members since a national walkout on budget day on 20 March.
Stoppages on Thursday 30 May include the National Gallery and Tate galleries in London and Liverpool. This will be followed on Friday 31 May by walkouts from the Natural History, Science and Victoria and Albert museums in London; and National Museums Liverpool where strikers will be forming a human chain around one of the main sites.
Staff from a range of other government departments and agencies will also strike on Friday, including the Land Registry, which was recently told it faces an increased threat of privatisation, and Department for Transport.
On Sunday 2 June the union's members at English Heritage sites, including Stonehenge, will be on strike.
Last week the union's annual conference agreed to hold a fresh national strike towards the end of June if the government continues to refuse to negotiate on these issues. Dates will be set at a later date and co-ordinated alongside other unions where possible.
Strikes on Thursday 30 May will include: National Gallery and National Portrait Gallery; Tate galleries in London and Liverpool; Department for Culture, Media and Sport headquarters; and Imperial War Museum.
Strikes on Friday 31 May will include: Natural History, Science, Victoria and Albert, and British museums in London; National Museums Liverpool (from 1pm to 1pm on Saturday); Department for Transport and its agencies, including the Driving Standards Agency and DVLA; Land Registry; Business, Innovation and Skills; Department for Energy and Climate Change; and research councils.
Strikers and supporters will form a human chain around the Museum of Liverpool, Pier Head, Liverpool L3 1DG, from 2.30pm on Friday to represent a defence of culture and the arts from government cuts.
PCS general secretary Mark Serwotka said: "These strikes highlight the huge gap between the valuable work our members do and the contempt being shown to them by ministers who are imposing cuts and refusing to even talk to us.
"Both in our cultural attractions that are known and loved around the world, and across the civil service, the government urgently needs to invest to improve services to the public and to help our economy to grow."