Lake Biwa 100 2026

The Lake Biwa 100 begins and ends near Ōtsu in Shiga Prefecture, adjacent to Japan’s largest lake. This October mountain ultramarathon, held in the Kansai region, covers approximately 100 miles (162-169 km) with significant elevation gain. It is not a simple lakeside path; participants navigate rugged mountains, technical ridges, forests, and trails near the water. The event hosts a small field of about 300 runners, and the 52-hour cutoff, while lengthy, still makes finishing a considerable accomplishment. The course is point-to-point, crossing the mountain ranges surrounding Lake Biwa, including ridges at approximately 1,200 meters and the Mt. Hiei area near the historic Enryakuji temple. Race organizers emphasize that speed alone is insufficient, as the course demands mountain navigation skills, risk assessment, and endurance across diverse landscapes. The finish line is located on the beach of Lake Biwa, allowing finishers to enter the lake. Miidera (Onjō-ji) and Ōtsu Port are nearby locations for post-race recovery.