Up to the village of Frossos, this stage coincides with the tracing of the PR4 ABL - Pateira de Frossos trail. In the initial route along the EN230-2 you have at your disposal a bike path, followed by agricultural paths that take you along the right bank of the Vouga River to the pulsating heart of Pateira de Frossos, an ecosystem incorporated in the Baixo Vouga Lagunar, of rich biodiversity and habitat of excellence for migratory birds and... birdwatchers. Along the banks corn plantations are abundant and as you enter the agropastoral mosaic, you can see that the land is limited by green corridors formed mainly by willows, alder trees, oaks, elders, among others, that constitute the "Bocage" landscape. From Pateira de Frossos to Albergaria-a-Velha, the stage coincides with Stage 6 | Segadães (Águeda) » Albergaria-a-Velha, of the GR58. It enters Frossos through the Boca do Carreiro Park, going through the village by its central street and passing by the Pillory and near the Parish Church of São Paio, standing out the decorative richness of the façades of the houses, in various types of tile, color and motif. The EM579 reaches the village of Frias and from there goes to Albergaria-a-Velha, where it enters for the EN16-2.