Approached to design the new municipal office in Nice, architect Sasha Sosno had a clear vision: a giant building shaped like the bust of a man with a solid box for a head. How to actually build it would require a brilliant blend of architectural innovation and improvisation.

La Tête Carrée Library, is a massive sculpture that stands at a staggering 85ft (or 28m) in height and was designed by French artist Sacha Sosno and made by two architects – Francis Chapus and Yves Bayard – for the Central Library in Nice. Entitled “Thinking Inside the Box,” the work is an accusatory and clear metaphor and hasn’t always been the most beloved work in the city, with locals often citing it as “ugly”. However, in spite of this, the building remains a fascinating tourist attraction and extraordinary structure, housing four storeys of offices and three storeys of book shelves.

Sosno, a sculptor and peer of other famous local artists such as Henri Matisse and Yves Klein, had long held hope to build such an unusual construction-sculpture but only got a chance to do so in 1997 when his idea was chosen for an administrative office of Louis Nucéra Library. Inaugurated in 2002, it was the first inhabited monumental sculpture in the world.

Located on the corner of Promenade des Arts, La Tête Carrée looks out over Place Yves Klein from the Jardin Maréchal Juin, a small public garden full of colourful flowers and a few more (albeit far, far smaller) sculptures. During the day, it simply looks like a massive sculpture of a head but, if you’re passing La Tête Carrée at night, it is lit from within by a lighting scheme devised by French light artist Yann Kersalé and you can make out the floors of the library inside.