Ostrvica, Volcanic mountain in Rudnik, Serbia

Ostrvica is a 758-metre elevation in the Rudnik massif, a remnant of a destroyed volcanic cone. It dominates the villages of Varnice, Zagrađe, Dragolj and Trudelj in the municipality of Gornji Milanovac. Remains of a medieval military fortification stand on the very summit.

In the Middle Ages Ostrvica's position and shape made it a defensive point, and a fortress was built on the summit; its remains are still visible there. Tradition attributes the construction to Jerina Branković, wife of Despot Đurađ Branković, who died in the nearby town of Rudnik.

Local tradition credits the fortress on Ostrvica to Jerina Branković, wife of Despot Đurađ Branković, known in Serbian folklore as Prokleta Jerina. She is said to have died in nearby Rudnik. The summit ruins are still linked to her name.

The volcanic rocks of Ostrvica are easily accessible and allow for walks to different points on the mountainside. The ascent requires basic hiking skills but is manageable for most visitors.

The fortress ruins on the summit are linked by tradition to Jerina Branković, wife of Despot Đurađ Branković, who died in nearby Rudnik. The peak is the remnant of a destroyed volcanic cone, and the site was declared a nature monument in late May 2009.