Morskie Oko, or Eye of the Sea (The name of the lake is derived from an old legend that the lake is connected to the sea through an underground passage), is the largest and fourth deepest lake in the Tatra Mountains, in the south of Poland. It is located deep in the Tatra National Park in the Rybi Potok Valley, of the High Tatras Mountains at the foot of the Mięguszowiecki peaks, in the Lesser Poland Voivodeship.
You have to give something to see the lake, because the walk to Morskie Oko is about 16 kilometers in total: over 8 kilometers (gradually) up, and the same way back down.
Duration of the walk: outward approx. 2.5 hours and back approx. 2 hours.