Croatia conjures up images of endless Mediterranean beaches, beautiful islands and dazzling Dubrovnik. And while no trip to Croatia would be complete without some time spent on the bright blue Adriatic, the Plitvice lakes south of Zagreb are a must.

When we were planning our trip to Croatia, a 20-something friend of our daughter said we had to see the Plitvice lakes. She had been there during her gap year and said that they were awesome. So we checked these unpronounceable lakes out in the guidebook.

They are in the Nacionalni Park Plitvicka Jezera, which was included in the Unesco list of World National Heritage Sites in 1979. The park is known for its many cascading waterfalls, turquoise clear lakes and rich forests.

These cascades and lakes, examples of karst hydrography, appear because of the process of tufa formation. Tufa is a porous carbonate rock formed by the sedimentation of calcium carbonate in the water. These create tufa barriers in the river, which either retain the water, forming lakes, or force the water to tumble over natural barriers and gush down like champagne bubbling over. We were enthralled. We had to see it for ourselves.

The park is huge, which means that you need to plan your day carefully. Give yourself at least six hours to explore. The information centre at the main entrance is informative and well managed.

We took a bus to the beginning of the series of lakes that are open to the public. We then walked along boardwalks through lush, green vegetation, featuring endemic flora, passing endless lakes and waterfalls. It had rained the day before and water seemed exceptionally plentiful. The paths were flooded and the spray from the waterfalls came down on us like rain.

Then we took a ferry trip across the largest lake, Jezerokozjak.The last part of the trip was again on foot and ended dramatically with the climax of the whole show, the Veliki Slap (The Big Waterfall).

Nothing can prepare you for the beauty and majesty of these lakes. No camera can completely capture the beauty of waterfalls that resemble bridal veils shrouded in mysterious mists.

There are 1 267 different species of plants in the park, creating a kaleidoscope of different hues of green. The water is so clear that you can clearly see the trout swimming beneath the surface, beside the busily paddling legs of the lakes’ numerous ducks.

One of the first people to research this natural phenomenon was Ivo Pevalek. In 1937 he said, “There are lakes, waterfalls and forests elsewhere, but Plitvice lakes are unique.”

They are unique, although another example of a karst lake system occurs in Castilla-La Mancha in Spain.

It was here that we discovered that the 15 Lagunas de Ruidera had been created in exactly the same way as the Plitvice lakes and that these two lake systems were the only examples of this style of karst hydrography in the world.

In Spain, as the Guadiana River meanders through its dry landscape, its course is interrupted by a series of lakes like a string of blue beads of water formed by the tufa natural barriers. The intense turquoise is caused by light reflecting off the carbonate dissolved in the water. The vegetation around the lakes, which ranges from forest to marsh, contrasts dramatically with the more arid parts of Castilla-La Mancha.

The Ruidera lakes, although beautiful, are not as spectacular as the Plitvice lakes. But there is plenty for visitors to enjoy. You can swim in some of the lakes, and we thoroughly enjoyed a swim in the cool waters after a walk in the 40°C heat.

El Hundimiento is the largest of the cascades. It is small compared to the Big Waterfall (Veliki Slap) in Croatia. We were there in the dry season, so perhaps there is more water after the rains, as the name Ruidera might suggest. We heard that in the wet season water flows from one lake to the next in noisy cascades, or “roideras”.

There are a numerous ducks and waterbirds including mallards, coots and moorhens.

These two lake systems, so similar and so different, are at opposite ends of Europe, and a great joy to see. - Weekend Argus

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