The lake was formed after the recession of the Bohinj glacier. It is up to 2120 m long and up to 1380 m wide, its maximum depth being 30.6 m and tectonic in origin. After the last Ice Age, the Bohinj glacier deepened the natural tectonic hollow and gave into its present form. The basin was filled with water when the ice melted. The lake has no large natural tributaries; it is fed only by a few springs.




The thermal springs in its north-eastern part are led into three swimming pools - Grand Hotel Toplice, Hotel Park and Hotel Golf. The picture-like image of Lake Bled is highlighted by the island in the western part of the lake.