Due to its unique shape, Izvor Cetine – or Cetina River Spring – is also known as the “Eye of the Earth”. The water that jets out from underground forms a natural pool and spills into a nearby river feeding it with fresh spring water. About 105km down the line and the cold water flows towards the Adriatic sea, in the town of Omiš.

Aside from this, this incredible karst spring is at the foothills of the Dinara mountain range in the country, Croatia. It is one of the best and coolest places to see on the Dalmatian coast

This karst spring has 155 meters of depth. A karst spring is part of a karst hydrological system with sinkholes and caves. This Croatia karst spring reminded us of the cenotes in Mexico and the Sac Actun underwater cave system in the Yucatan Peninsula.

The cold karst spring in Croatia is quite the opposite of our beloved hot springs that we chase around the world. People have described the temperatures of Cetina Spring as icy cold but that has not stopped people from swimming in the river. The river’s temperature is between 4C and 8C (46F). It’s practically an ice bath.

In 1972 the State Institute for Nature Protection declared the sources of the Cetina river a hydrological natural monument.

According to the Internet