I came across an interesting article from the Economist magazine two years ago: "Light on a lonely rock", talked about the Fastnet Lighthouse on Ireland's south-west tip at the mouth of the Atlantic and calls it "a monument of man's gift to mankind." The above's two pictures of the lighthouse. This article gives a brief history of lighthouse building that started 261 BC with Ptolemy I's building of the Pharos of Alexandria that stands over 400 feet tall with an open bonfire that could be seen 29 nautical miles away. At 177 feet high, the Fastnet light can be seen easily over 22 miles away.
What interests me is the comment by a former keeper that in stormy winter weather, the “big seas would come sailing up over the entire building like the field of horses in the Grand National.” In particular, Dick O’Driscoll, a keeper who spent 14 years on the rock, remembers a storm in 1985
"when a wave reached as high as the light and came crashing through the glass, overturning the vat of mercury and sending the poisonous liquid pouring down the stairs. He doubts the tower would have withstood another wallop as great as that, but it never came."That could be considered as a freaque wave at different circumstances. This one only stayed in the keeper's memory and did not go into any records simply because it did not cause any damage -- so it's like that falling tree in the forest that did not make a sound!
Speak of Pharos of Alexandria, the following is a Youtube segment from History Channel's recounting. What I found it's remarkable and somewhat disheartening is that it stood only for about 1500 years and now it's not there anymore. Nothing is forever!