Vitosha (Bulgarian: Витоша [ˈvitoʃɐ]), the ancient Scomius or Scombrus,[1] is a mountain massif, on the outskirts of Sofia, the capital of Bulgaria.

The mountain emerged as a result of volcanic activity and has been subsequently shaped by the slow folding of the granite rock layers and a series of gradual uplifts of the area.

Bulgaria's longest cave – Duhlata, with a total length of 18,200 m, is situated in Vitosha in the karstic region near the village of Bosnek.

The name Vitosha comes from the two-peaked, twin ridge mountain, which rises above the Sofia field and has acquired its present shape in stages over many millennia.

Historical documents show that several centuries ago Vitosha mountain was still covered by the remains of the inaccessible "Great Bulgarian Forest" (Magna Silva Bulgarica).

Today, the natural coniferous forests of Vitosha remain only in the reserve Bistrishko Branishte and around Zlatnite Mostove (The Golden Bridges).

Their further formation occurred due to the spherical erosion of the sienite rocks and their gradual movement to down stream valleys by the forces of gravity and moving water.