Derdap (pronounced Djerdap) is the second largest natural park of Serbia, after Prokletije, found at the border with Albania and Montenegro. Derdap is a vast forest and mountainous land of 600-650 sq km, comprising some villages. The most spectacular part of this landscape is created by the gorges of Danube, an impressive view created by the most important European river breaking through the Carpathian mountains, running wild between natural walls of rock at about half of its usual width.
During this segment, Danube also acts as natural border between Serbia and Romania, so the views are just as interesting though different from both banks.
The most important features of the park are the two cauldrons (small and great) created by the river (Veliki Kazan and Mali Kazan). They are named like this because the rushing water creates whirlpools that seem to be boiling in a cauldron. One of these is only visible by boat from the Romanian side, so crossing over to Serbia offers the possibility of seeing it from the road that winds along with the Danube.
To cross the river you use the Iron Gates dam, that also acts as a bridge and a check point. It is a joint venture between Romania and Yugoslavia during communism which modified the landscape to create a hydroelectric plant.
Another addition made after the Revolution of 1989 is the statue of Dacian king Decebalus, the largest stone sculpture in Europe. Found in a gulf on the Romanian side, near Mraconia Monastery, it is visible from both sides of the river.
An older artifact upstream the Danube is the medieval Golubac fortress, found near the largest city in the area. You can find hotels in Golubac, but also stay in the villages around it, at the welcoming locals.
Not far from the Iron Gates, there is Drobeta Turunu Severin, where Apollodorus of Damascus built the largest bridge of Antiquity, to help the Roman legions cross into Dacia. On the Serbian side, upstream of the Kazans there is an ancient stone inscription, known as Tabula Traiana, inscribed by emperor Trajan, and in which he is named as the commissioner of that bridge, after reminding the long list of political, military and religious titles and achievements that the Roman Emperor held.