This famous Art Deco advert for Chilean nitrate has been standing at the beginning of the Calle Real since 1929. It was designed by López-Durán Lozano, who was a student of architecture at the time, although he went on to become a professor at the School of Architecture of Madrid.
The tiles were made by the Valencian firm Ramon Castello.
Chilean nitrate was a fertilizer made of sodium nitrate (NaNO3), mined in the Atacama dessert of Chile. These days most fertilizer is made by extracting nitrogen from the atmosphere.