Natural History Museum has some fantastic resources, including virtual tours and lots of ‘how to’ videos such as make a beeswax wrap and nature journal https://www.nhm.ac.uk/take-part.html
Great Fire of London http://www.fireoflondon.org.uk/
Mr T does Primary History https://www.mrtdoeshistory.com/home-learning-packs
Virtual tour of Tutankhamun exhibition.
Year 4 were planning to go to see this once in a lifetime exhibition in London, but unfortunately this has had to be ceased. However, now you can see this online: https://tutankhamun-london.com/enter-the-tomb-vr-experience/
The British Museum has virtual tours and you can explore their collections https://www.britishmuseum.org/
University of York have 3 activity packs which are suitable for KS2 children (Year 3-6) https://www.york.ac.uk/archaeology/schools/