How to pronounce “curtain wall” in English

When Ley sculpted the gap-toothed ramparts of her keep, like castles from the kind of Schwarzwald fairy tale picture books where kids got eaten,Kai said, "You see, that's the tide line up there, where the seaweed's drying." When Ley carved a curtain wall with a bright blue trowel,packing wet sand between her palms, Kai said, "Your wall's too thin to keep the water out." "It's not to keep the water out," Ley said.