A view inside one of the distinctive spiral staircases of Clapham North Underground Station on the Northern Line, part of London’s deep-level tube network completed in the 1920s. The cast-iron stairwell descends nearly 120 feet below ground, wrapping tightly around a central ventilation column used to regulate air pressure and temperature within the tunnels. The staircase, equipped with yellow anti-slip edges and a steel handrail, was designed as an emergency exit and maintenance access route for the deep-bore platforms below.

Stations like Clapham North, along with its twin Clapham Common, are known for their rare narrow island platforms and compact circular shafts — relics of early tube engineering when space and construction methods were limited. The robust riveted metalwork and industrial geometry of the stairwell reflect the period’s emphasis on function and endurance, forming part of London’s complex subterranean infrastructure still in use more than a century later.