Jerusalem. Particularly the Kotel (Western/Wailing Wall) the remains of the second temple.
Jereusalem where Christ died and rose again (see Gospels).
There are quite a number of such sites, but the most famous is the Temple-Mount/Noble-Sanctuary area in the Old City of Jerusalem. It is the holiest site in the world to Jews and the third holiest site in the world to Muslims.
Yom Kippur
Yom Kippur.
The Dome of the Rock Shrine does not relate to Judaism. It relates to Islam. The actual "rock" in the Dome of the Rock, is the considered by Jews to be the holiest part of the Temple Mount and therefore the holiest place in the world for Judaism. (However, since Jews believe that only the High Priest can visit such a holy site, Jews are forbidden by religious law to come any closer than the Western Wall.) The Shrine itself is a Muslim holy site.
That depends when. Before they were exiled all over the world, the Jews were in Israel.
The holiday in question is YOM KIPPUR.
No. Yiddish is a language. Yiddish is spoken primarily by Eastern European Jews. The language is a hybrid of German, Polish, Russian, Ukrainian, and Hebrew. Concerning what is the holiest day in Judaism is, Jews disagree. There is the stance that every Shabbat (every Saturday) is the holiest day in Judaism. There is also the approach that Yom Kippur (a holiday that occurs sometime from mid-September to mid-October) is the holiest day of the year because of the capacity that Jews have on that day to atone for their sins before the Lord. Each of these two opinions has its merit and supporting arguments and each is true in a sense.
Jews regard all of the books of the Hebrew Bible as holy. The holiest part of the Bible are the first 5 books, called, "The Torah".
Jews believe that Jerusalem, Israel is their holiest city. Muslims have three holy cities: Mecca, Medina, and Jerusalem.
Yom Kippur also known as the days of Atonement is the holiest day of the year for Jews .