Crveno Jezero

Red Lake

Useful Information

Location: Hercegovačka ulica 5B, 21260, Imotski.
Near Imotzki. A1 E65 exit 29 Zagvozd, towards D62/Zagvozd/Imotski, D76 for 11 km, turn right, then left to Perinuša, then Proložac.
(43.454564, 17.199074)
Open: no restrictions.
Fee: free.
Classification: KarstTiankeng
Light: n/a
Dimension: VR=-528 m. V=16,000,000m³m. T=7.9 °C at 50 m below the water level.
Guided tours: n/a
Photography: allowed
Accessibility: yes
Bibliography: Dr. Bernd Aspacher, Ralf Haslinger, Ulrich Meyer, Anke Oertel (2000): Beyond the Blue, NSS News, May 2000, Vol 58, #5, pp 141-149
Prof. Dr. Mladen Garažič (2001): New Speleohydrogeological Research of Crveno jezero (Red Lake) near Imotski in Dinaric Karst Area (Croatia, Europe), International speleodiving expedition "Crveno jezero 98". Proc 13th International Congress of Speleology, Brazil 2001. Vol 2 pp 168 - 171 survey, biblio. [pub 2003]
(2006): Fauna Crvenog Jezera by Marijana Cukrov, Subterranea Croatica, Vol 4 No 6 June 2006, 64 pp, many photos, 2 loose surveys. ISSN 1334-5281. pp 23-27.
Published by Speleo Klub "Ursus Spelaeus", Kurelceva 3, 4700 Karlovac, 47000 Croatia.
Address: Crveno Jezero, Hercegovačka ulica 5B, 21260, Imotski
Modro I Crveno Jezero - D.o.o. Za Trgovinu I Građenje, Ul. Hajduka Andrije Šimića 12, 21260, Imotski, Tel: +385-21-841-657.
Biokovo-Imotska jezera Geopark, Ante Starčevića 3, 21260 Imotski, Tel: +385-98-892-552. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1998 explored by Aspacher, Behrend, Haslinger, and Hilbert.
1999 deepest dive to -181 m.
2014 construction of new trail started by the GeoPark.
2016 entrance fees for visits to the Blue and Red Lakes introduced.


The Crveno Jezero (Red Lake) is one of the deepest karst lakes or water-filled Karstdolines in the world. However you call it, it looks like a deep hole with nearly vertical walls and a deep blue lake at the bottom. The walls have some small caves, one of them starts above water level and ends below water level in the lake. But the visible part continues below the water level. Surveyed -281 m the lake goes even deeper. The deepest point registered by a Remotely Operated Vehicle (ROV) was -236 m. The deepest point reached by cave divers in 1999 was -181 m.

The Red Lake and its neighbour Modro Jezero (Blue Lake), a little smaller and just a few hundred meters away, are the surface signs of an underwater cave system deep below. Probably they were formed by the collapse of the same cavern below. Both have blue lakes at the bottom, and while the Blue Lake was named after the colour of the lake, the red lake was named after the red colour of the walls.

Anne Oldham and her daughter Christina describe a trip taken in 1986:

Back in Split we headed for Imotski, the site of what must be one of Europe's if not the world's most spectacular karst phenomena, yet one which is surprising little known, the Crveno Jezero, the Red Lake and the Modra Jezero, the Blue Lake, two deep, waterfilled poljes. Neither of these was mentioned in any of the guide books we read, nor have they been commercially developed. Once you are in Imotski they are easy enough to find, though it took Christina to spot the subtlety of the signposting, directions to the Red Lake are printed in red, those to the Blue Lake in blue.

The Red Lake is more accessible, one drives to a parapet, parks and peers over. It takes its name from the red rocks surrounding it, which look almost quarried, they are so sheer from the top of the cliffs to the bottom of the doline 518 m below. The doline which is about 200 m across, contains about 250 m of water, depending on the season, and its bottom is only 6 m below sea level. There is no foot access for tourists, but cave entrances can be seen in the sides. By the parapet is a memorial and wreath to a local boy who was thrown down the pit in 1942, not by the Germans, but by political opponents amongst his own countrymen, in what was then in effect a Civil War between the Cetniks, pro-Serbian, anti-Communists who were supported by King Peter's Government in exile in London, and the Communist partisans, who were led by Tito. The boy who was thrown down was on Tito's side.

The Blue Lake is higher on the hill, and consists of a doline 288 m deep at its lowest point, about 500 m across, and with up to 105 m of water in the bottom depending on the season. The colour of the water varies from green to blue, depending on how cloudy the sky is, blue sky, blue water, hence the name. The bottom of the doline is 239 m above sea level.

It is possible to climb down into this doline, and swim in the water. What a climb it is though, especially in summer. The first part is on a path, fallen away in places, the last part is down a scree slope.

The obvious cave entrance facing you as you descend does not go but you can't tell until you get there - I know I scrambled over the brambles in the hot sun to find out. The Kik-Kak cave encountered halfway down the path only goes for about 15 m.

The first view of the doline is quite breathtaking, a still, deep pool, many meters below, and the first impression does not diminish as you go down. We were there on a Sunday and pretty well had the place to ourselves but for some local boys, swimming or diving off the sides. Few tourists seem to know of the site or bother to descend when they find it. We thought it was great, but be warned , it is a long way down, far further than you think, and, as the doline acts as an airless heat-trap, the return trip can be very dehydrating on a hot day as there is little shade.

from: Anne Oldham: Yugoslavia 1986. Published privately by the author. pp 57-59 illus. With kind permission.