The Porta Nuova stands adjacent to the Palazzo dei Normanni (Palace of the Normans) on the Corso Vittorio Emanuele (popularly called the Cassaro), the primary artery of the city which leads to Monreale. Tension between the Spanish rulers and the Turks determined most of the changes to Palermo during the 16th century. The Porta Nuova was originally commissioned in 1583 by Viceroy Marcantonio Colonna to commemorate the earlier victory of Charles V over the Turks. This was destroyed in 1667 when stored gunpowder exploded. It was rebuilt in 1669 by the architect Gaspare Guercio. from Italian language Wikipedia. It features four herms or telemons of Turkish captives and a majolica tile pyramidal roof.