About this journey

The journey departs from Split station, where the line immediately passes through a 1,893 m cut-and-cover tunnel beneath the city centre before emerging on the north side of the Split peninsula. From here the train calls at stations along Kaštela Bay, running over the section of line that has carried a suburban metro service since 10 December 2006. This coastal stretch, built in 1888 and historically known as the Dalmatian railway, forms the older southern portion of line M604.

Beyond Kaštel Stari station the route begins a sustained climb away from the bay, crossing into the hinterland through a series of short tunnels and over terrain that rises well above 250 m before dropping into the Primorski Dolac valley. At Perković station the M607 line from Šibenik joins from the west. The line then works through Unešić and on toward the Čikola canyon and Petrovo Polje valley before descending to Knin station, the main railway junction in Dalmatia. The segment between Gračac and Knin was the final link opened, on 25 July 1925, completing the Zagreb–Split connection amid great celebrations after construction had begun in spring 1913.

North of Knin the climb intensifies through the Butižnica valley, with a wide loop out of the city and a succession of short tunnels. The line traces the edge of Velebit Nature Park, passes the Zrmanja river valley, and reaches the line's summit nominally at 793 m above sea level near Malovan station before descending through multiple tunnels toward the Lika valley. The Cerovac caves, discovered by a railway survey engineer in October 1913, lie just below the track near the abandoned Cerovac halt. Gračac station sits at the southern end of the broad Lika valley at around 550–570 m above sea level, offering a sharp contrast to the Mediterranean shoreline where the journey began.