The route continues on towards Furnas beach, but it is worth stopping to visit the bridge over the River Sieira, close to the waterfalls of the same name, taking us back to medieval times. The bridge is a slightly pointed stone arch, part of an old King’s Highway under the shade of a riverbank forest. The current leads to the nearby beach of the same name, forming a lagoon that allows you to bathe in fresh water right by the sea. Its almost white unspoilt sand and gentle waves are joined to Furnas beach by a wooden walkway. For many of you this beach will no doubt look familiar, as it was where Alejandro Amenábar filmed his well-known film The Sea Inside. River Sieira-As Furnas are the last beaches that we will visit in the town of Porto do Son. They are also a regular destination for the holiday makers who walk along the beach, just less than one kilometre long, with a surface of sand and rocks, as if it were a promenade.