Yellow polymeric aluminum chloride generally used drum drying production or spray tower drying production, there are flake, powder two solid forms.

黄色聚合氯化铝一般采用滚筒干燥生产或喷雾塔干燥生产而成，有片状，粉状两种固态形式。

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There is also the Powder Tower, a striking 15th Century fragment of the original city walls, at which the occasional medieval fair is staged.

BBC: Beside the Baltic seaside

Your starting point is the Powder Tower.

BBC: Geocaching Travel 101