Spell Factory at Town Hall 16: max level 9. It unlocks at Town Hall 5. Max level per Town Hall: TH5 1, TH6 2, TH7 3, TH8 3, TH9 4, TH10 5, TH11 6, TH12 6, TH13 7, TH14 7, TH15 8, TH16 9, TH17 9, TH18 9.
Tap a Town Hall to open this item there. Dashed: not available at that Town Hall yet.