This is a Camino for anyone seeking silence. You can walk for hours here without seeing another pilgrim, along old roads that few people use. The route is named after Diego de Torres Villarroel, a professor from Salamanca who walked this way to Santiago in 1737. On some stretches the yellow arrows are missing. A GPS track on your phone is not a luxury here but a necessity.
You start in Spain, crossing open, rolling countryside towards Ciudad Rodrigo. At Vale da Mula you cross the border into Portugal. The interior there is hilly and peaceful, with places such as Trancoso and Lamego along the way. After Mesão Frio it gets tough: a climb of 390 metres within 5 kilometres, and the next day brings another steep climb just like it. Via Guimarães and Braga you reach Ponte de Lima. There you join the Caminho Português Central and it gets busier. At Tui you are back in Spain. From there you walk via Pontevedra and Padrón to Santiago.
Walk this route in May, June or September, when the weather is at its kindest. From November to January and in March it is cool and often rainy, with up to 16 days of rain a month. That makes the steep sections harder than they need to be.