Purim is a Jewish holiday that celebrates the biblical story of Ester, a queen who saved the Jewish people from an edict decreeing their death, which was passed by Haman, the advisor to the king. (It's kind of a complicated story, so if you're not familiar with it I recommend checking out the link here, which has a longer version.) in practice, Purim is israel's answer to Halloween plus St. Patrick's day plus a little bit of Marduk Gras thrown in. Everybody (adults, children, dogs, literally everybody!) dresses up in costume and there are street parties and concerts and huge festivals all over the country. I spent the first two nights of our break in Tel Aviv getting a feel for the Purim celebrations there before returning to Jerusalem on Sunday for the last night of the festival.