Sion

Sion appears in the Old Testament as a name for Mount Hermon in Deuteronomy 4:48: Mount Siyon (that is, Hermon) — an alternate name for the great peak on the northern border of Israel, not to be confused with Zion (Jerusalem). The same form Sion appears in the Septuagint for both Hermon and Zion. In the New Testament (KJV and some versions), Sion transliterates the Greek Sion which renders the Hebrew Zion — thus Hebrews 12:22 (you have come to Mount Sion), Romans 9:33, 11:26, and Revelation 14:1 all refer to Zion as the heavenly or eschatological mountain of God. The spelling Sion in the KJV is simply a transliteration variant for Zion throughout the New Testament.