Festival of el Primer Viernes de Mayo de Jaca Activity · Jaca, La Jacetania, Huesca Image of Jaca, not of the place itself. Festival of National Tourist Interest that re-enacts the legendary victory of count Aznar Galíndez over a Muslim army in the year 758, with hundreds of local people in period dress. primer viernes de mayo Photo: Ecelan (CC BY-SA 4.0) What to see and do in Jaca