Comprising a 23m / 75 foot white tower with a gallery and other architectural details picked out in buff colour and topped with a black-painted lantern, Stroma Lighthouse is located on top of low cliffs at the northern end of the island of Stroma in the Pentland Firth. It lies at the corner of a walled compound that also contains the former light-keepers cottages and ancillary buildings. Built in 1896 to mark the dangerous waters of the Swilkie, it was the work of David A. Stevenson (1854 - 1938) and Charles Stevenson (1855 - 1950). The Swilkie is an almost-continuous whirlpool driven by the coming together of contrary tides.
Originally, a Trotter-Lindberg light system was installed. This used a rotating screen to permit a pattern of flashing and burned petroleum spirit or lythene, that had to be replenished at least once a fortnight. This was later replaced by a paraffin lamp which needed a smaller fuel reservoir.
In 1972, the light was converted to use an electric lamp, a sealed-beam unit mounted on a gearless revolving pedestal, and a helicopter landing pad was built nearby to permit simpler changeover of light-keepers. The light was automated 1994-97 with power now provided by batteries which are periodically recharged by a generator. At the same time a new optical system, with a 250 watt metal-halide lamp, was installed that had previously been used in Sule Skerry Lighthouse. The air-driven foghorn was removed (although its tower remains) and replaced by an electric fog signal located on the lighthouse balcony. The light now has a range of 20 nautical miles (37 km).
A plaque on the lighthouse commemorates John Calder, one of the lighthouse keepers, who fell to his death from the tower on 22nd April 1910. On 22th February 1941, the lighthouse was machine-gunned by a German aeroplane. No-one was injured, and the limited damage was quickly repaired.
