Vitosha 100km is a 100-kilometer mountain race on Vitosha Mountain, just outside Sofia, Bulgaria. It is run over a June weekend and is timed by Race Timing BG, a Sofia-based race timing company.
Runner accounts describe a course that starts biting after the first 10 kilometers, with technical sections early on. A flatter 20-kilometer stretch lets people settle into pace before a long climb toward Musala Hut, then a descent toward Zheleznitsa village, and one more climb before the finish.