A section from the spiral escalator (or spiral elevator) at Holloway Road station

Buried at the bottom of a lift shaft for 77 years, this spiral escalator was an engineering experiment ahead of its time. It was designed by inventor Jesse Reno and installed in an unused lift shaft at Holloway Road station in 1906. The spiral escalator consisted of two spirals encircling a central core - an outer spiral for the descent, and an inner one for the ascent. It ran continuously in a clockwise direction, travelling at a speed of 100 feet (30 metres) a minute. The journey to street level took approximately 45 seconds. It's likely that safety concerns prevented the complex machine from ever being used. It was dismantled in 1911, and the remains were discovered in 1988 at the bottom of the lift shaft during maintenance work. In 2010 a four metre section was restored.