Długi Staw Gąsienicowy — literally 'Long Pond of the Gąsienica Valley' — is one of the most quietly captivating glacial lakes in the Polish Tatras. Sitting at 1783 m above sea level beneath the rocky western slopes of Kościelec peak, it rewards visitors with a sense of wild, unhurried beauty that is increasingly hard to find in the mountains.

The lake stretches 254 metres in length and 100 metres in width, covering just under 1.6 hectares, with a maximum depth of 10.6 metres. It sits in a classic glacial cirque, fed by a stream descending from the higher Zadni Staw Gąsienicowy, and is itself connected by a stream to Niżni Czerwony Stawek. In summer the calm water mirrors the sky and surrounding ridges perfectly; in autumn golden grasses frame the shoreline; in winter and early spring the terrain can be icy and should be approached with care. The atmosphere is remote and intimate — far from the busiest Tatra trails.

• From Karb Pass — connector trail, approx. 20–30 min, moderate difficulty

• The lake lies within Tatra National Park — leaving marked trails and camping are strictly prohibited.
• A very rare protected sedge, Carex lachenalii, has been recorded at the lakeside — found in Poland only in the Tatras.
• A small cave called 'Schron przy Źródle' is located close to the lake.

Interesting fact: in 1960 brook trout — a species non-native to the Tatra ecosystem — were introduced into the lake. Local highlanders once knew it by the charming old name 'Kuklaty Staw', a little piece of folk history worth keeping in mind as you walk the valley.