Zelenci Nature Reserve

From the roadside parking lot, a flat, well-maintained trail leads through a coniferous forest to the lake. Wooden boardwalks bridge the marshy sections. After 5–10 minutes, you reach the lake – an irregularly shaped pool of turquoise-green water so clear you can see bubbles rising from underground springs through the chalky lake bed. The water maintains a constant temperature of 5–6 °C (41–43 °F) year-round, which means it never freezes, even in the depths of winter.

A wooden observation tower stands at the lake's edge, offering an overhead view of the water, the Drni marsh, and the Ponce mountain range to the south. Information boards in four languages (including English) explain the local geology, flora, and fauna. The surrounding reeds shelter rare nesting birds, and large trout are visible in the water. The Drni marshland stretches 1,200 m long and 150 m wide behind the lake.

The atmosphere is quiet and intimate – this is not a mass-tourism site but a place for calm nature observation. On summer mornings before 9:00, you may have the reserve nearly to yourself. By 10:00 on weekends, the parking lot fills and tour buses arrive. The best light for photography is early morning, when mist rises from the water.

Water color – emerald-green caused by chalky lake bed and underground springs bubbling up through the substrate

Temperature – a constant 5–6 °C (41–43 °F) year-round; the lake never freezes

Size – 47 ha reserve; the Drni marsh stretches 1,200 m long by 150 m wide

River source – the lake is the second source of the Sava Dolinka, Slovenia's longest river (940 km to the Danube)

Rare species – common rosefinch, European adder, sand lizard, and whiskered bat – all on Slovenia's endangered species list

Observation tower – wooden platform with overhead lake views and orientation boards in 4 languages

Zelenci formed after the retreat of the Planica glacier, which carved the Upper Sava Valley. The lake is a remnant of the ancient glacial Lake Koren. The underground Nadiža creek, originating in the Planica Valley, seeps through water-permeable gravel and re-emerges through the porous chalk lake bed. The name comes from the Slovenian word "zelen" (green). In the 19th century, British naturalist Humphry Davy visited the area and described it in famously glowing terms.

In 1992, Zelenci was officially declared a nature reserve by the municipality of Jesenice. The site is classified as a Natura 2000 area for its geological and biological importance. Chalk was quarried here until 1985. In recent years, the reserve has been modernized with wooden boardwalks, an observation tower, and multilingual information panels. A café and playground operate near the entrance.

From Kranjska Gora (5 km, 5 minutes):

– By car along road #202 toward Italy; parking on the left after Podkoren village

– By bicycle on the bike path toward Rateče – 15 minutes, flat route

– On foot – 50–60 minutes via Podkoren

– Bus to Podkoren (Rateče direction), then 15-minute walk

From Bled (43 km, 40 minutes):

– By car via A2 through Jesenice and Kranjska Gora

– Bus Bled – Kranjska Gora (€9–11, ~1 hour), then taxi or bike

From Ljubljana (90 km, 1 hour 15 minutes):

– By rental car via A2 motorway through Jesenice. Vignette required

– Arriva bus to Kranjska Gora (€9–11, ~2 hours), then 5 km to the reserve

Season: Beautiful year-round. Spring (April–May) brings wildflowers; summer has the most vivid water color; autumn features golden larches. In winter, the unfrozen green lake against white snow creates a striking contrast.

Time of day: Early morning (before 9:00) – fewest visitors, best photo light, gentle mist over the water. Sunset is also excellent.

Duration: 30–60 minutes for a visit.

Avoid: Summer weekends 10:00–16:00 – parking overflows and trails get crowded. Arrive early or visit on a weekday.