Šmit’s or the Green Lake is located in the village of Ivanac on the slopes of Velika Kapela in Ogulinsko Zagorje.

In this mountainous part of Croatia, which is characterised by karst, there is a lot of groundwater and many springs, streams, underground rivers, as well as underground and aboveground caves. Karst is a type of relief that develops on the ground which is composed of soluble rocks (most often calcium carbonate or magnesium carbonate). The basic characteristic of this kind of relief is the solubility of the rock. The consequence of this is a relief full of hollows and high ground. As karst usually develops in mountainous terrain, we, in this part of Croatia, are particularly rich in karst relief and other phenomena which goes with it.

The karst watercourse has little water on the surface, but a lot of water underground. The watercourses are typically short underground rivers, so a lot of water flows underground and dissolves the rocks.

In this place, the Green or Šmit’s Lake in the village of Ivanac near Ogulin is connected to several karst phenomena over a 100-metre surface.


Rupećica – the term Rupećica combines several mutually connected karst phenomena over a small distance. It is a spring, cave, a watercourse, sinkhole and a pit.

Water from the Rupećica karst spring flows to the Malo (Small) Lake through a series of fissures. From the Malo Lake – the water passes through shallows into Veliko (Large) Lake where it also descends.

It is here that various rare species of fauna have been discovered – this place is one the largest habitation sites of olm (Proteus anguinus) in Croatia.

Also found here is the river fish the Croatian dace (Telestes polylepis). This fish is special amongst Croatia’s endemic species. It is covered with tiny scales, which glitter when illuminated, and this is what gives them their Croatian name Svjetlica (“little light”).

In the dark depths of the Green Lake, a colony of the Ogulin cave sponge (Eunapius subterraneus) was also discovered. The Ogulin cave sponge is the only known freshwater sponge. It is attached to the rocks of underground channels or under large stones. They do not move, but they do filter water in order to feed on the small particles which come down under the ground. It lives in complete darkness so it has no pigment and is white.

Long ago, Šmit’s Lake – the name which is used today – was called the Green Lake because of its green colour. It consists of two connected lakes, Malo and Veliko (Small and Large). The Large or Green i.e. Šmit’s Lake is 60 metres long and 30 metres wide. The Small Lake is 30 metres long and 15 metres wide.

Both lakes formed at the intersection of two fissures – from Rupećica to the Small Lake and from the Small Lake to the Large Lake.

The Small Lake is 7.5 metres deep and the Green Lake is 23 metres deep and at the bottom is a vertical fissure that gradually narrows and becomes unpassable except by the water.


Šmit’s Lake took its name from a gentleman named Mr Šmit. Long ago, a family from the town arrived came once a year to the village of Ivanac, and they chose a young woman who would serve them for in return for a place to live, food and allowance. So the girl went with the family, however, after some time she returned with a husband, Dragan Šmit, and they settled near the lake. As he was a very sociable man, they often had guests, and the people from the village who would arrive would say “Let’s go to Šmit’s.” And so the Green Lake became Šmit’s Lake.

A legend is also connected to this place, which says that a long time ago, a terrible dragon, captured and kidnapped – a girl. St George appeared and saved her, and allegedly at Šmit’s Lake even to his day there is a stone that bears the “imprint” of the hoof St George’s horse.

On the Fairy Tale Route in Ogulin – the themed route which unites the creativity of Ivana Brlić-Mažuranić with locations in the town and its surroundings, at Šmit’s Lake there is an installation of a dragon. There is also a board on the Fairy Tale Route which marks Quest from Ivana’s fairy tale ‘How Quest Sought the Truth.’

If you come to Ogulin, at Klek mountain or in the surroundings, seek the truth, the dragon, a respite, karst, tranquillity, take a peek into this corner where the water spills from the rocks into the lake and then descends, leaving an emerald, deep, mystical and mysterious note to every moment spent here. If you are at the lake on a beautiful day, pay attention to the look of the lake – it is in the shape of a heart when the sun is above it.


This emerald green karst watery forested phenomenon – in the heart of the Ogulin region it will leave you inspired – not to mention how much potable water you can drink here – and the view and thought of the depths, the greenness, the underground, aboveground, the forest… however and whatever – deep in nature and within the reach of the village, the town and the roads.

If you need an interpreter – here I am.

Source: Speleolog 58 – The Croatian Biospeleological Society

Translated by Martin Mayhew