In and out of Spain and Portugal: a road trip up the Guadiana River

Bristling with castles and old port towns, the river that forms much of the Iberian border is peaceful and characterful – and you don’t have to start off on a zipwire

Strapped into a harness, hands clamped to a metal bar, I flew – at terrifying speed along 720 metres of zipwire suspended over the Rio Guadiana – from Spain into Portugal.

I’d taken a boat from Alcoutim (on the Algarve side of the river) to Sanlúcar de Guadiana (in Andalucía). From there I was driven up to a launch platform on a rocky summit with jaw-dropping views of both countries. Did I scream? As I hurtled towards Portugal, I tried to focus on those views: two dazzling white villages, the wide green river below, a castelo on one side, a castillo on the other. It was all over in less than a minute, but thanks to the international time difference I gained an hour.