The Great Mill (Wielki Młyn) was put up by the Teutonic Order around 1350 on an artificial channel, the Radunia canal, cut to bring water power into the town. It is a single enormous brick block under a steep roof, and it was the largest industrial building in medieval Europe: twelve water wheels at first, later eighteen, about 5 m across, nine to each long side. It burned in part in 1391 and was extended westward. It ground grain continuously until 1945.
What survives. In 1945 the mill was gutted — the west gable collapsed, the east side was damaged, the roof and all the machinery burned — and only the perimeter walls stood. It was rebuilt in 1962–65, and for years afterwards it held a small shopping arcade, which is what most older guidebooks describe. The wheels are gone and the interior is entirely new. What you get is the medieval envelope, its scale and its site on the water, with a modern museum inside.
The Amber Museum moved here from the Prison Tower and opened on 24 July 2021, tripling its exhibition space to close to 1,000 m². The lower floor deals with the material: Baltic amber as fossil resin roughly 40 million years old, how it forms, the roughly 300 fossil resins known worldwide, and the inclusions — insects and plant matter caught in resin and now under glass. The upper floor deals with the work: amber cut, turned and inlaid from antiquity to now, historic caskets and altars beside contemporary jewellery, and the story of the Amber Room, to which Gdańsk craftsmen contributed.
This is the entry that explains everything you will then see on Mariacka street. Gdańsk was an amber town under the Teutonic Order — the Order controlled the beach gathering rights and the guild that worked the stone — and the trade is genuinely medieval, unlike most of what is sold as such along the waterfront.
It is a ten-minute walk north of St Mary’s, past St Catherine’s church, and it is free on Mondays.
