Every autumn, from September to November, over 60,000 migratory birds of prey, known as raptors, pass through the Organbidexka pass in the Basque Country. This narrow mountain passage in the Pyrenees is a vital migration route for several species, including griffon vultures, black kites, imperial eagles, and cinereous vultures. These birds rely on this route because there are no other viable paths to Spain, making the pass an essential corridor for their seasonal movement. Since the 1970s, volunteers have been counting these birds, producing one of the longest and most detailed ornithological data sets in Europe, which helps scientists track the health of these populations. The high concentration of raptors at Organbidexka is due to the area's unique geography and wind patterns. The local topography creates thermal corridors—rising columns of warm air—that birds use to glide long distances without flapping their wings. This natural phenomenon is similar to a surfer riding a wave, allowing the birds to conserve energy during their migration. These thermal updrafts guide migratory birds from across Western Europe into a single, concentrated exit point, transforming the pass into a natural observatory for studying major migratory routes. Griffon vultures are often the first to arrive, beginning their migration as early as late August. They travel thousands of kilometers to reach sub-Saharan Africa, sometimes forming massive groups in the sky that can include hundreds of birds on favorable days. Black kites follow soon after, while imperial eagles, an endangered species, depend on Organbidexka as one of their last strongholds for observation in Europe. Cinereous vultures, though not strictly migratory, also use the same thermal currents as their migratory counterparts. Their large wingspans add a dramatic, almost prehistoric feel to the sky during migration. The data collected by volunteers over the past several decades provides researchers with valuable insights into the health of these bird populations. Changes in the number of different species can signal environmental threats, such as habitat loss or challenges in their wintering areas in Africa. Organbidexka is not only a breathtaking natural spectacle but also a crucial scientific observation site, offering a continental-scale view of the status and movements of migratory raptor populations.