Rob Bell heads nine miles out into the English Channel to see why building the world's first rock lighthouse was such a monumental achievement.
At Eddystone Reef, Rob witnesses the awesome power of rough seas and jagged rocks for himself, before a vivid demonstration of why building a tower on a wave-lashed rock was regarded as an impossible dream.
Lighthouses: Building The Impossible begins Friday 17th September at 9pm on Channel 5.