As of today, past peak, season runs to ~June 30. Earth Exhibit tracks the live conditions and flags it the moment it is on.
Lake Cerknica (Cerkniško jezero) in Slovenia's Notranjska region is the largest intermittent lake in Europe — a body of water that appears and vanishes with the seasons.
Fed by karst springs and sinking streams, the basin fills after the autumn rains and again with the spring snowmelt, spreading across roughly 26 km² to briefly become Slovenia's largest lake.
Then, through underground sinkholes (požiralniki), the water drains away and the lakebed dries into a patchwork of meadows and pastures where the same ground is grazed, mown, and even ploughed.
In a wet year the lake can persist for eight or nine months; in a dry summer it disappears almost entirely.
The cycle has fascinated observers since the 17th century, when Janez Vajkard Valvasor described its hidden plumbing to the Royal Society.
When full it is one of Slovenia's richest wetlands for birds and fish; when empty it is a walkable plain dotted with karst springs.
Where to see it
A taste of where to see it. The full map, exact coordinates and the best timing for each spot live in the app.
| Viewing spots |
|---|
| Dolenje Jezero Lakeside & Boardwalk |
| Slivnica Hill Panorama |
| + 1 more spot, with exact coordinates and timing, in the app → |
This is the short version
This page shows a taste. The app has the full list of where to see this, the exact timing, and live conditions for 1,000+ natural phenomena worldwide, so you know the moment one is genuinely worth the trip.