Open daily during the summer months, right next to the Hietalahti Market Hall, Hietalahti Flea Market, known among locals as Hietsu, is one of the largest and most popular flea markets in Helsinki. With about 150 vending stalls selling everything from gently-used clothing and household items to antiques and true vintage gems, the market is a great place to buy a unique treasure at a reasonable price. Just make sure you get there early and always have a modest amount of cash on hand!