st.catherine's chapel, abbotsbury, dorset

the stair turret does not lead out onto a walkway, the upper parapet is merely a wall adding mass to counteract any spreading tendency of the vaulting inside. visible for miles by sea or land, the chapel was built c.1400, probably as a pilgrimage chapel on a previously pagan site, as earthworks spiral around the summit of the hill. possibly a light in a brazier was on top, otherwise there seems no need for such a stair.