"Mirror of the Sky" Uyuni Salt Marsh - The world's largest salt layer covers the wasteland, pure heavenly Bolivian Uyuni salt marsh, is the world's largest salt marsh. The lake is like a mirror, reflecting the beautiful suffocating sky, water and sky, dreamlike. This is the legendary "mirror of the sky", the closest place on earth to heaven. Uyuni Sky Mirror only has a large area of water every year during the rainy season of January to March. This is the time for Uyuni's true strength. Photo Raiders: When the water surface is calm and windless, the mirror effect is best, and the red clothes are better.