Cruising from Bucharest to Vienna on the MS River Explorer.
The most scenic section of this voyage is the so-called Iron Gate gorge where the Danube cuts through the Carpathian mountains. This section lies between Romanian Transylvania on the left bank and northeastern Serbia on the right. There are two dams and three locks to make the river navigable through this stretch. A double lock near Milanovac uses unusual vertical gates rather than swing gates.
There is moderate river traffic through this voyage, heaviest in the upper reaches between Budapest and Vienna.