Stretching over an area of 120 km, from Bazias to Portile de Fier, Danube Gorge is the longest gorge on the Danube and unique in Europe through the grandeur of its configuration.
It has a series of basins alternating with gorges in the Large and Small Boilers, having a width of 150m.

Following the construction of the Iron Gates hydroelectric power plant, through the dimension of the new retention pond, the Danube Gorge and especially the Boilers area have escaped the horror of the churning water through the straits marked by steep slopes.

They were called "boilers" because here, through the corridors with fjords, the seething and boiling water seemed dark.
River’s trail formed a zigzag shape, as it made room for its bed among the rocks. This can be seen today from any vehicle deck ship, which once arrived in the Large Boilers passes through a golf to another bypassing the rocks that suddenly appear in front of it, but this setting is not scary anymore.

The tranquility of the lake goes up to the entrance of the Danube in the country at Bazias and continues all the way to Belgrade.
Starting from Orşova in Eselnita, the entrance to the Small Boilers begins. The road through the gorge can be travelled on water or on land. The road is carved into the rock in several portions.
While the vessel approaches Ogradena, on the Serbian side you can read the inscription on the Tabula Traiana, recalling the road the Roman legions took in the years 101-104, when craftsmen cut the mountain to build the road on the Serbian side. At km D 967.3 Ciucarul Mic wall is split by Valea Mraconiei.

Here we see carved into the rock, the Dacian image of Decebal and Mraconia monastery as if rising from the river.
At km D 970, the lake suddenly widens to form the Dubovna gulf, from here up going into the display of the Large Boilers, where the Danube crosses the white slopes of Ciucarul Mare (maximum elevation 318 m) and opposite the Veliki Strbac (maximum elevation 768 m) here the riverbed has a minimum width of 150 m and a maximum depth of 80 m.

The grandeur of the Large Boilers can only be seen here sailing the Danube because the road travels behind the massive mountain.
Displaced along with the damn buit between the Danube and the Iron Gates, the villages from the gorge still carry in their soul the drama of drowning their homes in the barrier lake.

On the left bank of the Danube, 4 km downstream from Sviniţa (County), there is the Tri Kule Fortress, which was built in the fifteenth century to stop the Ottoman expansion westward.
The Tri Kule Fortress was represented by three towers placed on the Danube shore in the form of a triangle. The Tri Kule Fortress ensemble was flooded following the forming of the Iron Gates I barrier lake and now you can only see two towers.