Imotski Lakes
The Red and Blue Lakes at Imotski
Some of the world's largest sink holes are close to Imotski in Croatia
Names in Croatian are: Modro Jezero (blue lake) and Crveno Jezero (red lake)
How to find the lakes
Both lakes are very close to Imotski. From Komarna you can choose two roads:
The fast road using the motorway towards Split and leaving at exit Zagvozd. The toll was 12 Kuna in 2011. From the exit follow the road signs towards Imotski. You enter Imotski on road 60 from the east.
Or the slower, but shorter road going through Bosnia & Herzegovina. Drive to Metkovic, turn over the bridge towards Ljubuski. Pass the border outside Prud and continue towards Imotski. Just before Imotski you pass into Croatia again. You enter Imotski on road 60 from the west.
In both cases drive towards the city center when you arrive at Imotski and you will see plenty of signs directing you to the lakes.
The Blue Lake
The Blue Lake is a deep sinkhole formed by the collapse of the roof over a huge underground cave. The cave was formed by water through millions of years, and it collapsed about 5 million years ago. Erosion and earth quakes have formed the sides of the lake so it is now possible to walk on a path all the way down the 220 meter deep sides.
Water depth in the lake varies a lot by season as it is fed by several small streams coming out of caves in the high walls of the lake. In August the lake may completely disappear if there has been no rain fall.
The Red Lake
From the Blue Lake there is a short 1 km. walk to the Red Lake. The lake is named after the red cliffs that form its walls, and it is one of the biggest sink holes in the world. The total depth of this sink hole is 522 meters, and it drains out in a strong underground river of unknown origin and destination. The lake was formed by the collapse of a huge cave millions of years ago.
In the lake lives a fish that is unique. It was named Delminichthys adspersus as late as 1843 and is a small sardine looking fish of 9 to 12 cm. The fish can occasionally be found into the Trebisat river and in the rivers and stream of the flat land below Imotski, and it suggests that there is wide spread underground connections between the rivers.
The Fortress
Above the town and the Blue Lake towers Fort Topana built by a Croatian duke in the 9th century. It played an important part in the Ottoman occupation from 1493 to 1717. Since the Turks left it lost its importance and was abandoned more than 100 years ago