Kasprowy Stawek is one of the Tatra Mountains' best-kept secrets — a tiny forest lake that appears and disappears with the seasons. Visit in spring and you might find a proper little pond; return in autumn and you could find nothing but dry ground. That unpredictability is exactly what makes it so intriguing.

Tucked away in the Kasprowa Valley in the Polish Western Tatras, this small lake sits in a hollow on a moraine ridge that separates the Sucha Kasprowa Valley from the Stare Szałasiska valley. It is fed entirely by underground springs, and its water drains away underground too — which explains why its size can vary so dramatically. In May 2006, it measured 40 × 13 m with a depth of 1.5 m; by October of the same year it had dried up completely. At high water, a second smaller pool forms right beside it. Surrounded by coniferous forest and set near deep karst sinkholes, the atmosphere here is quiet, slightly mysterious and well off the beaten path.

• Kasprowa Valley is accessible from Zakopane — starting from Kuźnice or via Jaworzynka Valley. Forest terrain, moderate approach.

• The lake lies within Tatra National Park — leaving marked trails is not permitted.
• Spring offers the best chance of seeing the lake at full size; in late autumn or dry summers it may be completely absent.

Although shepherds grazing the Hala Kasprowa pastures knew of this little lake for centuries, it was not described in scientific literature until 1933, when Stefan Zwoliński wrote about it — making it one of the Tatras' last 'discovered' natural features.