Helical staircase of Santo Domingo de Bonaval Curiosity · Santiago de Compostela, Santiago, A Coruña Image of Santiago de Compostela, not of the place itself. A triple spiral staircase designed by Domingo de Andrade in the convent of Bonaval: three independent flights coil in the same well and come out on different floors without ever crossing. Photo: User Alma (CC BY-SA 3.0) What to see and do in Santiago de Compostela