In the past, the railway track connecting Tanvald and Kořenov was famous for its unique cogway, which allowed trains to climb the steep mountain terrain. The entire railway track has been declared a technical monument, including the 932m tunnel between Dolní Polubný and Kořenov, for the construction of which 20 tons of dynamite were used. The 25m high viaduct near Zelené údolí in Kořenov is also worth visiting. Another interesting fact is that the railway station in Kořenov was built on an embankment created from 800,000 m3 of soil. The whole Jizera Cog-Wheel Railway certainly belongs to the ranks of technical curiosities and it is frequently visited by rail history enthusiasts.