A hidden gem

Meaning

A place or thing that is not well known but is very good.

Examples

• John: Have you heard of that new restaurant downtown?
• Alice: No, which one?
• John: The one on Elm Street. It's <b>a hidden gem</b>; the food is amazing!
• Alice: Oh really? I'll have to check it out. Sounds like <b>a hidden gem</b> I need to discover.