Đerdap National Park & the Iron Gates on the Danube

Đerdap National Park lies in eastern Serbia along the right bank of the Danube, where the river marks the border with Romania. The gorge, popularly the Iron Gates, runs roughly 100 km from Golubac to Tekija and ranks among Europe's longest breakthrough gorges. The park was founded in 1974, named Serbia's first UNESCO Global Geopark in 2020, and made a Ramsar site the same year. It holds about 1,100 plant and 150 bird species. Opening details aren't claimed without source checks; where unsure, we say we don't know. (Source: Wikipedia, Wikivoyage)

Golubac Fortress is the park's western gateway, rising on the Danube's south bank about 4 km downstream from the town of Golubac. It was built in the 14th century in medieval Serbia and grew into a complex of three compounds and ten towers; the first nine stand 20-25 m high, while the tenth was an Ottoman addition. After an EU-funded 2014-2019 restoration, it reopened to visitors in April 2019. Current hours and fees aren't stated without source verification; where uncertain, we say we don't know. (Source: Wikipedia, Wikivoyage)

Lepenski Vir is a prehistoric settlement on the Danube's right bank near Donji Milanovac. It dates from the Mesolithic into the Neolithic, roughly 9500 to 5500 BC. Found in 1960, it was uncovered from 1965 through excavations led by Dragoslav Srejović. It is known for trapezoidal houses and around 52 stone sculptures with fish-like faces. Because of the reservoir, the site was moved higher in 1971; today a glass-roofed museum protects it, declared a Cultural Monument of Exceptional Importance in 1979. Opening details aren't claimed without source checks; otherwise we say we don't know. (Source: Wikipedia, Wikivoyage)

The Kazan section is the gorge's most dramatic stretch. The Danube narrows from about 6 km at Golubac to 150 m in the Veliki Kazan; cliffs rise to some 300 m, and the greatest depth was measured at 82 m in Gospođin vir. The Roman plaque Tabula Traiana (about 4 × 1.75 m), carved into the rock, was raised higher when the dam backed up the Danube in the 1970s. Iron Gate I, completed in 1972, created Lake Đerdap, Serbia's largest lake. Boat details aren't stated without source verification; where unsure, we say we don't know. (Source: Wikipedia, Wikivoyage)

Golubac, Donji Milanovac, Tekija and Kladovo make good bases. From Belgrade you reach Golubac by car via Požarevac in about two hours. To see the Tabula Traiana and the Great and Small Kazan, many visitors recommend a boat trip between Donji Milanovac and Tekija; the road also has viewpoints. The roughly 110 km EuroVelo 6 cycle path runs through the park too. Current schedules, prices and opening details aren't stated without source verification; where facts are missing, we say we don't know. (Source: Wikipedia, Wikivoyage)