'Unique and remarkable' because the exhibition takes place only this one evening on this one day of the year, only in Pienza; because on this evening alone the delightful 'cortile' of the Palazzo Ammannati is open and illuminated as the centre of the small exhibition, together with the specially open cortili of the great Palazzzo Piccolomini and of the former Palazzo Jouffroy and Palazzo Borgia now the lovely town museum and, usually, the tiny cortile of the recently-identified former quattrocento inn; because every year the theme is different and every year fascinating, illuminating another select aspect of renaissance history , of Pope Pius II and of Pienza; and because the whole is the private initiative of an individual Pientino, Francesco Dondoli, and is organized and achieved by Francesco with his friends and fellow volunteers, combining highly professional results, élan, imagination, sheer hard work and impeccable good taste.
Francesco Dondoli has written about the genesis and development of 'Cortili aperti' in the first edition of Canonica, the periodical of the Centro Studi Pientini, which you can read in Italian here, with a portfolio of the elegant little catalogues for each edition of the exhibitions from 2005 to 2010 -- very much worth leafing through here even if you do not read Italian.
* 'Cortili aperti' may translate literally as 'open courtyards' but English is impoverished if we do not use the Italian 'cortile'. From the Encyclopedia Britannica on-line, for instance: 'cortile: internal court surrounded by an arcade, characteristic of the Italian palace, or palazzo, during the Renaissance and its aftermath'. Thus the lovely and most magnificent of Pienza's cortili, of Pope Pius's Palazzo Piccolomini: