They serve an ornamental function, to mark the entrance to the exhibition district, now known as Fira de Barcelona, and the start of the grand avenue leading up to the Palau Nacional on Montjuïc, which houses the National Art Museum of Catalonia. Originally, the towers were open to the public, who could climb the internal stairs to the viewing galleries, but they are now normally closed. In later years, the western tower housed equipment for controlling the illumination of the Magic Fountain of Montjuïc, 350m away at the far end of Avinguda Maria Cristina, and the gallery of the eastern tower housed sirens for signalling possible emergencies; the disused equipment was removed during the 2013/14 restoration work.