This is the Grand Synagogue in Budapest, its the biggest in Europe and No.2 in the world (the #1 is actually in New York)
This is both a live functioning place of worship and also a museum at the same time.
The French flag is there for a waiting place for a tour guide. There are tours for Hungarian, English, French, Spanish, Russian and Hebrew speaking visitors. This is a truly incredible looking temple, every fitting and decoration appears to have done with the utmost quality and case.
This spiral staircase looks great, I ended up seeing another later when I went to Trinity College (which is Christian, in Dublin, Ireland) On the right, a big collection of candelabras used for lighting Shabbat candles.
I think Hungary was hit very hard by the Shoah (Holocaust) but there are items from then, and also from happier times when this was a bustling place for celebrating Jewish holidays.