The former military tower in which Buck Mulligan and Stephen Dedalus are staying has living quarters on the second level and battlements on the third. A steep stone passage of "dark winding stairs" connects these two stories, from whose "stairhead" (shown in the center of the photograph) first Mulligan and then Stephen emerge into the open air.

JH 2011

Photograph of the roof of the Sandycove tower, showing the "stairhead."

Cutaway view of typical Martello tower. Source: Wikimedia Commons.