turnpike 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.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Tower with internal turnpike stair and demolition of existing extension at Archibald, Moffatt House, Academy Street, Moffat - granted.
Built on five floors, with the original turnpike stair, flagstone and timber floors, accommodation includes a barrel vaulted banqueting room with elevated minstrel's gallery and a medieval-style loo with concealed 20th century plumbing and copper basin.