Con Dao Prison, also known as Phu Hai Prison, is a historical site that played a significant role during the French colonial era and the Vietnam War. It was a place of immense suffering for political prisoners. Today, the prison has been transformed into a museum that showcases the harsh conditions and brutal treatment endured by the inmates. Visitors can explore the prison cells, view photographs, and learn about the island's dark past. It is a somber but important place to understand the island's history.