Gravel Birds Ultracycling

Gravel Birds Ultracycling sends riders out of Castro Verde into the open plains of Baixo Alentejo for a self-supported week on some of the emptiest gravel in southern Europe. The organisers are clear that it is not a race: there are no prizes or podiums, drafting is banned, and everyone gets by on what they carry and what they can buy in the same village cafés and shops. Riding alone, in pairs or in small groups is all fine, and their guidelines put it simply: slow is okay.

The loops begin in the Castro Verde Biosphere Reserve, a UNESCO-listed patchwork of cereal steppe known for great bustards and lesser kestrels, then head into country that keeps changing character: the Guadiana Valley and the Islamic heritage of Mértola, the abandoned São Domingos mines with their rusted machinery and strangely coloured lagoons, and the lonely, steep tracks of the Serra do Caldeirão on the Algarve border. The longer loops add a stretch along the Atlantic cliffs of the Costa Vicentina, and the biggest one swings north to Évora and the hilltop village of Monsaraz above the Alqueva reservoir. Past riders, and the organisers themselves, warn that the short, sharp climbs add up to far more than the profiles suggest.

Behind it is ACAN (Associação Ciclismo Aventura e Natureza), a non-profit based in Castro Verde that sees adventure cycling as a way to bring life to Portugal's overlooked interior, and part of every entry fee goes to local nature conservation groups. The first edition in 2022 had 14 starters; by 2025 well over a hundred riders from many countries were taking part, with places now allocated through an application process to keep the event small enough for the land and the villages it passes through.