Both are thousand-year-old festivals to showcase and honour the work of local artisans. Along the winding streets you'll find old-fashioned tools and machinery, sculptures, wood and stone carvings, textiles, masks, toys, and other items made from copper and wrought iron, creating an atmosphere of what life might have been like in a village in the Aosta Valley a thousand years ago.
In Donnas, the Friday preceding the fair is the Veillà , during which townspeople open their cantinas to visitors and musicians and singers roam the narrow streets entertaining the crowds. On Saturday evening, Mass is held at the Cappella di Sant'Orso followed by a musical performance. Bright and early on Sunday morning, the fiera begins with displays from over 500 artisans; the fiera in Aosta features over 1000 exhibitors.
As for the saint whose name is attached to the fair, not very much is known about Sant'Orso, or Saint Ursus, the most popular saint in Aosta, but his feast day is February 1, and he is said to be of Irish and/or Scottish origin and lived during the 6th century.
Here is a look at the Fiera di Sant'Orso, including displays, music, and the open cantinas:
The 2009 festivities in Donnas will be held from 16-18 January, while those in Aosta are on 30 and 31 January. Find more information at Fieradisantorso.com and Fierasantorso.it.