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.
References in periodicals archive ?
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.
From the second you step inside the iron-studded door and walk among its archways and turnpike stairs, you're back to an era of jousting knights and medieval banquets.