Mysterious Island (1961)

Plot

Amid the turmoil of the US Civil War, a group of Union prisoners of war make a daring escape in a hot air balloon, only to crash land on a remote South Pacific island. There, they encounter a bizarre ecosystem filled with colossal flora and fauna. As they navigate the island's perils, these resourceful men must rely on their wits and teamwork to survive and find a way back to civilization. This adventurous tale serves as a sequel to the beloved classic '20,000 Leagues Under the Sea.'