Wolf Rock lies 8 miles off Land's End in Cornwall, UK, . This rock was a constant danger to shipping and a number of attempts to put a beacon on the rock were made between 1795 and 1850; finally a lighthouse was built on it between 1862 and 1870.
The rock is particularly dangerous as there is deep water virtually all around it. A swell surged over the rock even in good weather, so the construction was very difficult. James Douglass landed on the rock in July 1861 to survey it, and work started on a granite tower designed by James Walker in March 1862. That year only 22 landings were possible by the construction crew.
The stone blocks were cut, shaped and trial fitted together in Penzance. Just over 1000 tons of rock was needed for the base, and 3300 tons of granite used for the tower. The first 39 feet of the tower is solid, the a 7 ft 9 inch wall starts that tapers to 2 ft 3 inches by the time it reaches the top of the tower, some 116 feet above the rock. The final stone was put in place in July 1869, and the light first shone in January 1870. The oil-powered light was replaced by a generator-powered electric light in 1955.
With a range of 23 miles, the lighthouse's signal is one white flash every 15 seconds, and there is a fog signal which, when operating, sounds every 30 seconds.