When it comes to public sculpture Mexico City rules ok. You want fifty large sculptures down the side of a motorway? Not a problem. A bronze 1:1 replica of Michelangelo’s David in the middle of a square. Done. But the most daring example we've seen without a doubt is the installation of Gabriel Orozco’s whale Ballena three meters above floor level in a public library (the Biblioteca Vasconcelos) designed by Mexican architect Alberto Kalach. The library building itself is so immense that from the top floor even the whale’s massive skeletal form looks kind of small but from the lower floors it’s an astonishing sight. You can read how Orozco located the skeleton and made the work here.