The Castle Ralsko is the highest fortification of the Czech Republic, lying in 696 meters above the sea level. The path starts to climb up from the neighbouring village Vranov through a forest and the further you go, the steeper it is. On the top, which is 15m wide and 20m long, there are remains of castle walls. The castle was build from basalt. Even nowadays, the wall remains are 1,5 – 2,0 wide. Opposite the west side, there is the main entrance which used to have a circular watch tower, to the right there was a steep slope protecting the castle. In the narrow yard used to be stables, above them in the south a knight's hall with a two-storey tower.

If you climb up to the top, there is a wonderful all-round view of the Lusetian Mountains and the Ještěd ridge. You can see the former military training base Ralsko, a 3km-long runway and the beautiful panorama of hill and castle Bezděz and the unmistakable shape of hill Říp. Directly under our feet, there are the towns Mimoň, Stráž pod Ralskem and Jablonné v Podještědí.