Duel of skyscrapers and vineyards. | Along the Rhine and Main rivers, through vibrant cities and picturesque landscapes, we conducted the ultimate test for travel photographers. In Frankfurt, in the Upper Middle Rhine Valley (UNESCO World Heritage Site), in Würzburg, and at the Mainschleife, the top smartphones - Sony Xperia 1 VI and OnePlus 13 - competed against each other. Which delivers the best pictures during your travels?