helix stair

spiral stair, caracole, circular stair, cockle stair, corkscrew stair, spiral staircase

spiral stair
A flight of stairs, circular in plan, whose treads wind around a central newel. Also called a helical stair, solid newel stair.
References in periodicals archive ?
From the top level of the pedestal, visitors can view the double helix stairs leading to the Statue's crown as well as the support system designed by renowned French architect and engineer Gustave Eiffel.
From the top level of the pedestal, visitors can look up and view the double helix stairs leading through the interior of the Statue to the crown as well as the support system designed by renowned French architect and engineer Gustave Eiffel.
April 2009 marked the beginning of further improvements to the double helix stairs leading up to the crown, which reopened on July 4, 2009 for the first time since the terrorist attacks of September 11.