Walking through Čertova dolina just become easier Hiking Čertova dolina is manageable even during winter thanks to a new ferrata. New ferrata in Čertová dolina (Source: TASR/ Branislav Caban) Font size:A The mayor of the town, Irena Milecová, said that the ferrata will be open to visitors even in the winter. This was made possible due to a new walkway, called Jakub Surovec, that passes through the ravine, the TASR newswire reported. There was uncertainty and an exchange of opinions regarding the construction of the ferrata since it is located in a protected region. But those in favour argued that there are ferratas in Slovak Paradise, which is also a protected region.