Vtáčnik, Mountain summit in the Vtáčnik range, Trenčín and Banská Bystrica regions, Slovakia

Vtáčnik is a rocky summit at 1,345.8 metres in the main ridge of the Vtáčnik Mountains, on the border of the Trenčín and Banskobystrický regions. Its upper slopes are partly deforested and covered with mixed forest, while the broader central massif also includes Kláštorská skala, Zraz, Malá Homôľka and Veľká Homôľka.

Vtáčnik formed during intense volcanic activity in the Neogene period, creating the rocky foundation of the mountain. This geological history left the summit with its characteristic steep structure and mineral-rich composition.

The peak is the eighth stop on the Vtáčnik educational trail, which begins in Gepňárová Valley near Bystričany. The trail's panels explain the periglacial rock forms — kettles, cones and rock steps — shaped by frost and the weathering of andesite flows. The name Vtáčnik means "bird mountain".

Multiple marked trails approach the summit from the Žarnovica and Prievidza districts, each with different starting points and difficulty levels. Winter climbing requires additional gear and caution, as conditions change quickly at higher elevations.

The national nature reserve, declared in 1950, covers 245.62 hectares and protects the summit beech communities exposed to extreme climatic conditions. Similar stands elsewhere in the Carpathians arose mainly after spruce and dwarf pine were cleared, whereas here they are natural.