The Mysterious Island (1975)

March 23rd, 1885. Fighting rages in the city and the southerners gain ground. Meanwhile, five northern prisoners, accompanied by their dog Tob, manage to escape. In their escape from the enemy, they had no choice but to board a hot air balloon to survive the chaos of the terrain. It is then that the flying machine will take them to a mysterious place, perhaps even more dangerous than the war itself...