I gladly invite you to visit Blue Lake, which is the only lake in the world that changes colour depending on the light. It was formed by the collapse of a mining gallery on Miss Reef in the years 1919 - 1920. The color of the water is what gives the lake its uniqueness: bluish-green, sometimes with emerald reflections. When the mine is flooded due to sulfides, the lake water acquires a deep shade of green, with accents of blue. Moreover, when there are several people in the needle water, it changes its color to a strong blue. Blue Lake - Baia Sprie - Maramures is unique in Europe due to the way it was formed and due to a property, it has, namely that it changes color depending on the season (sun position, water temperature). In spring the lake is light blue and dark blue, in summer it is dark green and sometimes with emerald reflections, and this autumn it becomes dark green and sometimes brown. No one has yet given an exact scientific explanation for these changes so those of you...