How a 19th-Century Scot’s Harebrained Quest Shaped Sovereignty in Western Sahara

In the remote Moroccan fishing town of Tarfaya, a 19th-century British fortress is collapsing into the sea. An imposing cube of gray stone with hollow, arched windows and a line of spikes over the entrance, it stands on a reef facing Tarfaya Beach. At low tide it is accessible on foot, with nothing to stop visitors scrambling around its blackened interior or youths carving graffiti into the walls. At high tide, it is marooned by Atlantic waves that eat away at its foundations. The entire northwest corner has fallen, a ragged chunk is missing from the adjoining ground floor and an ominous crack extends up the south wall. Some think it will not last another winter.

Locals call it the Casamar — short for “Casa del Mar” or “House of the Sea.” This British fortress with a Spanish name in a Moroccan town bears witness to Tarfaya’s role as a historical buffer zone, whose fractious tribal politics have mediated the ambitions of nations and empires since the Casamar was built. Its fall will erase the last visible legacy of an episode that history has all but forgotten, but which lit the touch paper on one of the world’s longest-running conflicts.