I went on holiday to Nice in summer 2019 pre Covid. There is a memorial plaque to the victims of Nazism generally on colonnades between the shopping area and the sea front. There is also the Marc Chagal museum/art gallery near the rail station as he lived for a long time in Nice. However, it is mostly focused on his childhood in E. Europe, rather than his time in Nice. The Rothschilds/Effrussis also lived at Cap Ferrat near Nice in a rather opulent mansion. The Town Museum on the sea front mainly focussed on the 1960s movie industry when we were there, including its Jewish luminaries (the Pink Panther films were made there and some James Bond films). 

Jill Whitehead, Surrey, UK