Forum Trabzon is an one-stop shop for clothes, accessories and general supplies. No matter what you're searching for, chances are you won't walk out empty-handed.
You'll have to find your way to Ortahisar to reach this shopper's paradise. If you intend to do some sightseeing after you're done, why not head for Trabzon Hagia Sophia Mosque? It's not too far from Forum Trabzon.