Related Clues:

• Almost eternity
• Longish span of time
• Millennia on end
• Bronze and Iron, e.g.
• Ever so long
• Geological span
• Becomes drinkable, perhaps
• Grows old gracefully
• Iron and Bronze, e.g.
• History unit
• They change every year
• Iron and Stone
• Matures, as wine
• Loooong time
• It's comprised of ages and ages