Southeast of Gdansk, Malbork Castle was the seat of the Teutonic Knights, who had their headquarters here from 1308 to 1457. It is the largest medieval fortress in Europe. Covering 21ha, the huge red brick construction rises imposingly on the right bank of the River Nogat. Although the aged nature of the structure seems in places artificial, this castle (an icon for the 19C Romantic movement) has since 1997 been a Unesco World Heritage site.