aerial view of modern six-star hexagon d fort cittadella of alessandria on winding river tanaro. piedmont, italy.

aerial alessandria alps architecture back barracks bastions bridge buildings casemates citadel cittadella city ditches duchy empire europe fort fortification fortress hexagon italy kingdom landscape meier moats modern nature new old panorama piedmont plan ponte quarter ramparts regular river sardinia savoy shape shaped sixstar star starshaped tanaro towers town travel view walls winding