The traditional lighthouse lantern was framed with vertical metal struts holding rectangular panes of glass. The problem was the struts themselves: every vertical bar cast a finger of shadow across the beam, interrupting the light at exactly the moments a sailor most needed to see it. The engineer Alan Stevenson - whose family had been Scotland's lighthouse engineers for generations and would later produce the novelist Robert Louis Stevenson - solved the problem by setting the panes diagonally. The diagonal framework was structurally stronger, and the shadows fell in directions that did not blind any one approach line. Noss Head was the first lighthouse built to this design, and the Northern Lighthouse Board adopted it as the standard for every lighthouse it built afterward. A small piece of engineering history, born of the need to keep ships off the Caithness rocks.

Construction began at the urging of the Northern Lights Commissioners - the formal name for the Northern Lighthouse Board, which still maintains every lighthouse in Scotland and the Isle of Man. The white cylindrical tower rises 18 meters from the headland and supports a single gallery with a black cupola at the top. There are 76 steps to the top. The focal height of the light is 53 meters above sea level, and the beam reaches 25 nautical miles out into the Moray Firth and the Pentland approaches. The light characteristic is a flash every twenty seconds. The colour varies with direction: white over safe water, red over hazards - a coded language sailors learn to read at a glance through the spray. In October 2017 the original rotating optic was retired, and the Northern Lighthouse Board replaced it with a static LED beam. The light still flashes; it just no longer turns.

Like many British lighthouses, Noss Head was automated and the keepers' houses sold off. A private company bought the adjacent cottages for £200,000, and during their restoration the Northern Lighthouse Board collaborated with the new owners to renovate the whole station as a single coordinated project - tower, cottages, outbuildings - rather than piecemeal as funding allowed. When the work was complete, the local Member of the Scottish Parliament, David Stewart MSP, was invited to inspect both the renovated tower and the restored keepers' houses. From the cliffs around the lighthouse you can see the ruins of Castle Sinclair Girnigoe just to the south, three miles of coast that includes one of Scotland's most dramatic Sinclair-clan ruins and one of its most quietly important Victorian engineering achievements - the lighthouse that taught every other lighthouse how to shine.