Mount Agung, Bali's highest and most sacred volcano, is a challenging but rewarding climb for experienced hikers. Trekking to the summit typically requires a guided tour due to the difficult terrain and spiritual significance, with options ranging from overnight climbs to shorter day hikes on the lower slopes. Accessibility is limited due to the steep, rugged paths, and altitude sickness is a potential concern. Climbing is often restricted during certain Balinese ceremonies or periods of volcanic activity, so it's crucial to check local conditions and regulations beforehand. The cost can vary significantly depending on the tour operator and route chosen, ranging from $50 to several hundred dollars, and the duration of a typical summit climb is around 8-12 hours. Always hire a reputable guide, bring appropriate hiking gear, and be prepared for unpredictable weather.