The rocky ridge of Sisol is the southern part of the Učka ridge, from Kalić in the south to Šikovac in the north. The area can be experienced along the To Sisol excursion itinerary, which starts and ends in Brseč.

In the area of Sisol, the ridge of Učka narrows into a sharp ridge with extremely steep sides. The continental sides of the ridge are characterised by vertical rocky cliffs with a large area of scree beneath them. Besides Sisol (835 m), other prominent peaks are Šikovac (778 m), Bukovo (771 m) and Kalić (712 m). In the central summit area, there is an interesting geomorphological feature: the cave of Provrtenica, located under a natural rocky arch and open at both ends. The advantages of the area were recognised in the distant past when the prehistoric Gradac hillfort was built on the ridge, the ramparts of which can still be made out. The hillfort, as well as other parts of the ridge, offer attractive views of the surrounding landscape. The ridge is primarily covered in forest, while in its southern part there are prominent mountain meadows and pastures. Although parts of the ridge are still occasionally used for grazing, their area has been significantly reduced.