Fiestas de San Antolín Activity · Plentzia, Plentzia-Mungia, Bizkaia Image of Plentzia, not of the place itself. Plentzia's main festival, which opens with the traditional farmers' market and an inaugural rocket; it includes fancy-dress, marmitako, tortilla and fire-bull contests, with the "Alpargata de Oro" as its top prize. 2 de septiembre Photo: Gunnar E. Heßke (CC BY-SA 3.0) What to see and do in Plentzia