Crveno Jezero Imotski

Crveno Jezero, the Red Lake, is a collapsed karst sinkhole near Imotski that holds dark water at the bottom of near-vertical cliffs. It is among the deepest such lakes in Europe: the rim sits hundreds of metres above the surface, and the water itself drops further still. The name comes from the iron-stained red rock that marks the walls.

The lake formed when the ceiling of a large underground cavern caved in, leaving an almost circular pit. There is no easy way down to the water, and swimming here is not really the point; the spectacle is the scale, best taken in from the rim above Imotski.

Together with the nearby Blue Lake, the Red Lake makes Imotski one of the more geologically theatrical towns in the country, and the two are easy to combine in a morning. The water level shifts noticeably with the seasons.

For photographs, a wide lens from the rim at golden hour catches both the red walls and the depth. Keep back from the unfenced edges; the rock is crumbly and the drop is real.

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