Notranjska is the region in the transition from Primorska to Central Slovenia. This is a karst landscape with world famous karst phenomena. Many use the term Notranjska Karst Triangle to identify the area between the Postojna basin, Planina polje, and Cerknica polje which covers the historically best known karst system. The Postojna Cave and the disappearing Cerknica Lake are world renowned, and there are numerous caves, sinks, and forested karst plateaus. All this natural wealth will be united in the Snežnik Regional Park, and cyclists will be able enjoy it along numerous trails. For the moment, these trails exist only around Logatec, Cerknica, and Pivka.
Bordered by the forested Javorniki ridge in the heart of Notranjska is the renowned Cerknica polje, which the rainy season fills with the disappearing Cerknica Lake. The mysteries of this natural phenomenon were revealed to the world three centuries ago by the Slovene polymath Janez Vajkard Valvasor, and still today, visitors marvel at the numerous karst phenomena around the lake and the diversity of migrating birds that find refuge here.
Signs showing the folk hero Martin Krpan, who once smuggled salt across this region, guide us along the bicycle trail. It leads from Cerknica, the largest settlement on the lake, on asphalt and dirt local roads, forest roads, and field tracks around the polje and across it, if it is not flooded, of course. The lake is ten kilometers long, and the marked bicycle trail around it leading past numerous interesting sights is about thirty kilometers long, but we can always shorten it. Tourist farms provide accommodation and a friendly atmosphere, and the lake offers pleasant and refreshing swimming in the summer months. Especially interesting to see is the relief model of the lake in the village of Dolenje Jezero in the middle of the polje that graphically illustrates the natural filling and draining of the lake. If you decide to come by train, the Rakek railway station is only a few kilometers from Cerknica.