Lo specchio di Diana (1996)

In 1926 the remains of two ships built by the Emperor Caligula were found at the bottom of Lake Nemi, near Rome. Mussolini had the lake drained and established a museum as a celebration of the imperial origins of Fascism, but the museum and ships were destroyed by fleeing Nazis in 1944. The film commemorates these events. - MoMA

Unfortunately the movie Lo specchio di Diana is not yet available on HBO Max.