The Guns of Navarone (1961)

In J. Lee Thompson's old-fashioned WWII action/adventure blockbuster film about an Allied commando team with a secret mission to neutralize a German fortress threatening Allied naval ships - with Oscar-winning Special Effects:

• the opening prologue with voice-over narration by James Robertson Justice - supplemented by images of the classic Greek monuments: "Greece and the islands of the Aegean Sea have given birth to many myths and legends of war and adventure. And these once-proud stones, these ruined and shattered temples, bear witness to the civilization that flourished and then died here and to the demi-gods and heroes who inspired those legends on this sea and these islands. But, though the stage is the same, ours is a legend of our own times and its heroes are not demigods, but ordinary people. In 1943, so the story goes, 2,000 British soldiers lay marooned on the tiny island of Kheros, exhausted and helpless. They had exactly one week to live for in Berlin, the Axis High Command had determined on a show of strength in the Aegean Sea to bully neutral Turkey into coming into the war on their side. The scene of that demonstration was to be Kheros, itself of no military value, but only a few miles off the coast of Turkey. The cream of the German war machine, rested and ready, was to spearhead the attack and the men on Kheros were doomed unless they could be evacuated before the Blitz. But the only passage to and from Kheros was guarded and blocked by two great, newly-designed, radar-controlled guns on the nearby island of Navarone. Guns too powerful and accurate for any Allied ship in the Aegean to challenge. Allied intelligence learned of the projected Blitz only one week before the appointed date. What took place in the next six days became the legend of Navarone"
• the tense scene of the team of commandos disguised as Greek fishermen on a dilapidated fishing vessel that was stopped, interrogated and inspected by a Nazi Germany patrol boat; the commandos were able to destroy the enemy boat and its crew
• the tense nighttime climb up the steep cliffs of the Navarone island (in the Mediterranean)
• the revelation of the traitorous Anna (Gia Scala)
• the climactic destruction of the two German super-gun emplacements (in a lofty impenetrable fortress cave above the Aegean Sea), by the placement of explosives on the rail of an ammunitions hoist-elevator, with fire spewing from the front of the cave entrance after detonation

The Destruction of the Guns and the Entire Fortress

• the last lines of dialogue between the two main officers after their successful mission, as they watched the fortress burning from afar from the deck of a destroyer: (Corporal Miller (David Niven): "To tell you the truth, I didn't think we could do it." Capt. Keith Mallory (Gregory Peck): "To tell you the truth, neither did I")