I say it like the word 'Zion', perhaps because of point 3 below, but may be wrong.
• ZION (noun)
The noun ZION has 3 senses:
1. originally a stronghold captured by David (the 2nd king of the Israelites); above it was built a temple and later the name extended to the whole hill; finally it became a synonym for the city of Jerusalem
2. Jewish republic in southwestern Asia at eastern end of Mediterranean; formerly part of Palestine
3. an imaginary place considered to be perfect or ideal