A recruit from Platoon 1085, Company D climbs to the top of the "Stairway to Heaven," an obstacle in the Confidence Course during the Crucible. The Crucible is a 54-hour training event conducted during Marine Corps Recruit Training at Edson Range, Marine Corps Base Camp Pendleton, Calif. The Crucible requires Marine recruits to overcome mentally and physically-demanding obstacles as a team. - A recruit from Platoon 1085, Company D climbs to the top of the "Stairway to Heaven," an obstacle in the Confidence Course during the Crucible. The Crucible is a 54-hour training event conducted during Marine Corps Recruit Training at Edson Range, Marine Corps Base Camp Pendleton, Calif. The Crucible requires Marine recruits to overcome mentally and physically-demanding obstacles as a team.