The Creach'h lighthouse marks, with the one of Land's End in Great Britain, the entry to the Channel, which is one of the busiest sea lanes in the world -- 50,000 ships per year. The Creac'h is one of the most powerful lighthouses existing today, whose signal (two white flashes every ten seconds) can be seen at 61 km. There is also a powerful fog-horn, which used to be operated by horses, but which today is, of course, automatic. There used to be a strange device, an underwater bell, too.