san niccolo weir in florence on a sunny day over arno river. view from lungarno della zecca vecchiain

architecture arno river beautiful blue city cityscape dam drought environment europe firenze flood control florence italy flow green historic italia italian landmark landscape medieval natural nature old outdoor outdoors riverbank niccolo santa rosa weir scenery sky stone stream structure summer tourism town tree tuscany view water waterfall sunny day lungarno della zecca vecchiain river vecchiain