On view through 3 November at the Botín Foundation in Santander is ‘Calder Stories.’ Eighty pieces of different origins are on display in an exhibition that is distinct for two main reasons. First, instead of centering around the American artist’s canonical works, it looks at projects of his that were never carried out – forgotten about, censored, or simply impossible to materialize – but which the curator, Hans Ulrich Obrist, deems important as bearers of unsuspectedly fruitful ideas. The show’s other mark of distinction is the collaboration of the building’s author, Renzo Piano, who has a special affinity with Alexander Calder. The Italian architect took charge of the exhibition design.