There aren't many races where the route map shows an international border crossing at the halfway point, but that's exactly what happens at the X Milhas do Guadiana. On Sunday, November 8, up to 1,000 runners will line up in Vila Real de Santo António on the Algarve and jog — or race — 10 miles (16.09km) into Ayamonte in Andalusia, Spain. It's the 31st edition of an event that dates back to 1992, when it launched to celebrate the building of the Guadiana International Bridge, the span the runners still cross today.

The start gun goes at 10am Portuguese time on Praça Marquês de Pombal, with the finish line at Plaza de la Ribera in Ayamonte. The field is capped at 1,000 athletes and open to both federated and amateur runners born in 2008 or earlier, so plenty of everyday runners take part alongside club competitors. There are proper prizes too: trophies for the top three men and women overall, age-group winners and the five best teams.

Support along the way is solid for a low-key border run — water stations at kilometres 5, 10 and 13 plus the finish, and medical cover at the start, on the course and at the end. Younger family members aren't left out either: the X Milhas Kids sends children born between 2016 and 2021 off at 10.15am.

Entry is a bargain at €10, but you have to commit early. Online registration closes at 11.59pm on November 5, places are assigned in order of sign-up, and there's no entry on the day. Race numbers can be collected on November 7 between 3pm and 6pm at the headquarters of Grupo Desportivo Pic-Nic in Portugal, or on race morning from 8.30am to 9.30am at Praça Marquês de Pombal.

The event is run jointly by the sports commissions of Vila Real de Santo António, Castro Marim and Ayamonte, along with local sports bodies on both sides of the river. It sits under the Eurocity of the Guadiana umbrella, a cooperation project that links these neighbouring municipalities through shared cultural and sporting events.

For travellers, this is a neat excuse for an autumn Algarve trip with a twist. November is mild on this coast, and the race effectively gives you two countries in one weekend — Vila Real's leafy grid-planned centre on one side of the Guadiana, Ayamonte's tapas bars and marina on the other. Even if you're not running, it's a fun spectator morning, and the area between the coastal towns and Castro Marim's salt marshes makes for good off-season walking. Just note that if you want a race number, you'll need to register well before you travel.