Hidden at 1672 m above sea level beneath the rocky walls of Skrajna Turnia, the Green Tarn — Zielony Staw Gąsienicowy — is one of the most striking glacial lakes in the Polish Tatras. Its signature light-green water, so clear you can see up to 10 metres deep, makes it look almost unreal on a sunny day.

The lake is the largest in the Zielona Gąsienicowa Valley and the eighth largest in the entire Polish Tatras, covering nearly 3.84 hectares with a maximum depth of over 15 metres. The remarkable green colour comes from a small amount of plankton suspended in the crystal-clear water. In spring, once the ice melts (usually May or June), the scenery feels fresh and raw. Autumn brings golden hues to the surrounding dwarf pine slopes before the lake freezes again in October or November — making every season a compelling reason to visit.

• Zakopane / Gąsienicowa Valley — black trail from Roztoka Stawiańska towards Świnicka Przełęcz; approx. 1 h 25 min to the pass (uphill), difficulty: moderate.

• The lake lies within Tatra National Park — staying on marked trails is mandatory and entering the water is not permitted.
• The rare Lachenala sedge, uncommon in the Carpathians, grows along the shoreline.
• The lake freezes October–November and thaws May–June.

The tarn was once known as Suczy Staw — legend has it that a dog which had been mauling sheep was drowned here, only to be found later in a distant cave. Today, only the lake's extraordinary beauty remains.