The hanging Spirals staircase. This design makes sweeping under the stairs easy! A hanging double spiral staircase is part of the Didden Village project in Rotterdam. There are two such staircases; the other is a single spiral.
STAIRCASE – one of the most unique circular staircases Ive ever seen. Very rustic, open, and custom. London, England: Medieval staircase displayed at the Victoria and Albert Museum. (Photo by Carol Estes) - House Decorators Collection