Welcome to the 100K BTR Ultra 2025 category!

The BTRU 100K is an all-new, ultimate test of endurance, designed for runners with the heart of an explorer and the courage of an adventurer. Known as the “Volcano to Volcano” challenge, this race spans an impressive 106.20 kilometers with a staggering elevation gain of 7,244 meters, all within a cut-off time of 34 hours. Only those who finish this category can truly be called brave and resilient, as the 100K journey is one of Bali’s most challenging and awe-inspiring ultra-trail experiences.

In the 100K category, participants will compete in both the Open and Masters 50+ years category. This race also counts toward the ITRA (International Trail Running Association), UTMB (Ultra-Trail du Mont-Blanc), and Asia Trail Master performance indexes, making it a valuable addition for serious ultra-runners. By completing this epic journey, you’ll not only boost your performance credentials but also gain a monumental achievement in your trail running career.

The 100K route will take runners on a dramatic journey from the volcanic slopes of Mount Batur to Mount Agung, the highest and most sacred peak in Bali. This adventure leads participants through some of the island’s most breathtaking landscapes, from dense forests to barren lava fields, steep hills, and high mountain ridges. This route is eagerly awaited by Indonesia’s trail running community, offering a complete exploration of Bali’s volcanic terrain and its stunning natural diversity.

The journey begins at Mount Batur, where runners will climb to the summit, taking in panoramic views of the crater and the volcanic landscapes. From there, the course descends southward to the black lava fields—an eerie, Mars-like landscape where the dark rocks and open night sky create an otherworldly atmosphere. This section of the route, illuminated by the stars, will give runners a unique, unforgettable nighttime experience.

Leaving Mount Batur behind, runners will navigate through the Buahan pine forest, which sits along the ancient Batur Caldera. This serene forest offers a brief respite before the course heads to the basecamp of Mount Agung, where participants will prepare for the race’s biggest climb. From the western side, runners will ascend the formidable slopes of Mount Agung, Bali’s highest peak. Here, every step is a challenge, but the views from the top are unmatched, offering a 360-degree panorama of Bali and, on clear days, neighboring islands in the distance.

The descent from Mount Agung brings runners west and east toward Mount Abang, with a route through scenic, untouched paths that showcase Bali’s rugged beauty. Climbing up Mount Abang from the eastern approach, runners will find themselves immersed in a lush, vibrant landscape, with views that make the grueling ascent worthwhile.

From Mount Abang, the course leads to Terunyan Hill, a sweeping savanna landscape with rolling hills, valleys, and open spaces that showcase Bali’s natural charm. As runners continue, they’ll descend into the traditional village of Terunyan, a place known for its distinctive Balinese customs and way of life. This rare glimpse into Bali’s rich cultural heritage will give runners a sense of connection to the land and people they are journeying through.

The course then challenges runners with a steep climb up Pedahan Hill, known as the “hill of hell,” where every ounce of remaining energy will be tested. This ascent is the final push, where the physical and mental strength of every runner is truly tested. The reward at the top is a sense of profound accomplishment and stunning views of the surrounding terrain.

The final segment of the 100K route takes runners through rolling vegetable farms, a peaceful and scenic end to this intense journey. The farms, tended by local communities, provide a gentle and fitting transition from the wild, rugged landscapes of the volcanoes to the cultivated beauty of Bali’s countryside.

The 100K BTR Ultra 2025 is more than just a race; it’s a journey through Bali’s heart and soul, an exploration of the island’s breathtaking natural and cultural landscapes. From the volcanic craters and dense forests to the serene villages and challenging ascents, every kilometer of this race is designed to inspire, challenge, and leave a lasting impression on each participant. For those who seek an ultimate test of strength, endurance, and spirit, this category is a chance to prove yourself and join an elite group of finishers who have conquered Bali’s toughest trails.

Register now to secure your spot in this monumental race, and prepare yourself for an adventure that will redefine the boundaries of trail running in Bali.

Are you ready to become a grandmaster of the 100K BTR Ultra? Join us and take your place among the bravest runners in the world!