Female rowers in Hibaika rowing club on a workout sesion, to get ready for the second stage of the 'Kontxa flag'. Donostia (Basque Country). September 4. 2017. This Challenge is one of the oldest and most famous rowing races along the Bay of Biscay, held annually in the Kontxa bay. It takes place on the first two weekends in September and regularly draws crowds of people. Men's challenge was first held in 1879. Since 2008, women rowers have their challenge. (Gari Garaialde / Bostok Photo).(Gari Garaialde / BostokPhoto)