The river Mrežnica is known to the general public as one of the four rivers of Karlovac. Although it is much shorter (64 km) than Dobra, Korana and Kupa, many people who know the rivers of Croatia will say, that Mrežnica deserves a special place among the rivers of the Croatian karst. What makes Mrežnica exceptional, are the 93 travertine waterfalls, which in some places of the flow make little lakes. It is not only the number of the waterfalls what makes Mrežnica exceptional. Although none of these waterfalls can't compete in height with the ones on Plitvice lakes or Krka falls, their picturesque shapes is what makes them unique, as spring as the river itself. What is especially interesting for this river is the position of these waterfalls. In the upper flow, from Čića's bridge to the Tržić bridge, in a length of only 5 km, there are 26 waterfalls, and there are as many in the lower flow from Generalski Stol to the place where it flows into Korana, but in a length of 39 km!
The spring of Mrežnica is in a cave beneath Popović peak (479 m). The spring, together with the 12 km of the flow is inside the military installation "Eugen Kvaternik". In the time when the installation was run by JNA, before the war in Croatia, the spring was damaged with a construction of a small hydro-electric power plant which was supposed to feed the installation with power in case it could not be obtained from the network.
After the first 7 km of its flow the river Mrežnica receives its first tributary Suvaća, and not far from here there is a bridge over it called Čuruvija's bridge. Mrežnica is mostly made of travertine, and in its upper flow there are numerous interesting travertine waterfalls and underwater dams. One of such waterfalls is Rončevića fall (4.1 m), which is about 2 km downstream from Čića's bridge, with three major travertine cascades over which water falls into a deep lakelike flow.
Immediately after Rončevića fall, under steep cliffs which form a narrow passage there is Milkovića fall (8m). This is the second largest fall on Mrežnica, and with its shape and the way in which, during low levels of water it practically delivers the water downward over a little "slide" formed on the middle of the fall, it belongs among the most beautiful falls on Mrežnica.
Several kilometers downstream the river goes into the narrowest canyon in its entire flow, and it runs through it all the way to Smoljanovića fall and to the bridge in Tounjski Tržić. In this part of only 1,2 km of flow, squeezed in a canyon full of vegetation, carved with white rocks, there are 9 waterfalls. In this part of the river there is a strong spring which brings down the temperature of Mrežnica in summer by 6-7 °C. The influence of this spring can be felt almost 5 km downstream, what is visible by different moss on the falls and the different shape of the falls.
Under Tounjski Tržić, Mrežnica is shallow and runs slowly. Reljića and Jagodića falls follow, and then Šušnjar. Šušnjar is the highest fall on Mrežnica with its 13 m. The fall surrounded a tiny, but deep lake between two cascades in a curve. On every side of the fall, entirely fitting into the landscape is one mill. Traces of the travertine rock on the right bank which is 4-5 meters high, and underneath which lies a cave, brings up the possibility that in the geologic past this fall was even higher, and the lower cascade was probably formed with the decay of the upper part.
Downstream from Šušnjar, in several smaller waterfalls there is a complex of Korać falls, and then there are Glavaš, Benić and Žara falls. There is a wooden bridge by Žara falls which connects the villages Dizdare and Vidovići. Although it lost its function a long time ago, an old bridge leaves a deep impression in its simplicity.
Klarića fall, in its amphitheatrical shape, cuts the flow of Mrežnica in almost half of a circle. On a steep cliff on the left bank of river Mrežnica there was once the city Ključ which was owned by the Frankopan family. The city was devastated a long time ago, and today it is hard even to find the ruins.
From the river Mrežnica, on the right bank of the river there is a beautiful view of Tounjčica running into Mrežnica. Although someone who is not familiar with the view, would think Mrežnica is a tributary of Tounjčica because Mrežnica falls over junction falls and there it receives Tounjčica, and suddenly changes its direction.
Strengthened by the waters of Tounjčica, Mrežnica continues its way through a mild canyon toward the north. After several falls there is a channel called Čikina luka, under which there are two smaller falls before Rebića fall. Rebića fall (4,5 m), also called Milin mill, is a wonderful third in its size, travertine giant which made a huge bow across Mrežnica. Then, there is the, twelve years ago, by dynamite heavily damaged Vitas' fall, which is luckily, through the process of travertine build-up, recovering.
The village Katići together with the weekend town of the same name, is the first larger inhabited area on Mrežnica and it is a sign of the beginning of more inhabited areas in the lower part of the river Mrežnica. On the bank of the river beneath the fall Malinice next to the village Mlinci, in the time of Austro-Hungarian reign, a steam water-pump was built, just like the railroad from Zagreb to Oštarije and further on. The pump was feeding water to the railroad station in Generalski Stol where the steam locomotives got their water supply.
Then there is a bridge in Keići which was destroyed in World War II, so a hundred meters downstream there was a ferry. The ferry on Mrežnica can be seen at Jankovo Selište where people use the ferry every day to reach the railroad station in Gornji Zvečaj. An interesting traffic object is a pontoon bridge, downstream from Puškarića fall in Gornji Zvečaj.
Several kilometers downstream the river again runs in a short but steep canyon. On the left bank not far from the village Novo Brdo there is a quarry. Under the vertical cliffs there is Kosov fall, under which Mrežnica reaches its greatest depths.
Downstream the river falls over several other falls, over Polović fall (lower) there is a picturesque wooden bridge which connects Belavići with Mrežnički Brig.
In the Duga Resa area Mrežnica has two more bridges crossing it. Above the northern bridge, on the river there is a small hydro-electric power plant of the small cotton industry of Duga Resa. From here Mrežnica puts on another face, which it holds until running into Korana in Turanj. You can feel the urban environment and there are more polluted places with trash to be seen. This "tamed beauty" remains in the memory of everyone who has seen it at least once, even from the old "Josephine road" on the way to the coast.
