Entre Túneis e Condutas is the longest section of the Water Route: 15.1 kilometres between Remédios and Água de Pau, using paths created to collect, convey and inspect water. Casa da Água marks the start and introduces an itinerary in which infrastructure is not a minor addition but the central subject. Bridges, aqueducts, channels, old clay pipes and technical buildings reveal solutions built in different periods.
The trail climbs through farmland and forest, sharing some sections with other routes. Tunnels pierce elevations that once obstructed the direct passage of conduits, while Janela do Inferno appears as a damp cavity in a vertical wall, with a spring and small pool. Farther on, Pico do Raposo and vegetation associated with watercourses add a natural layer to the corridor. Livestock and pasture keep the route connected with present-day rural use.
Near Pedras Brancas, PR42SMI meets the PR41SMI junction but continues on its own line towards Água de Pau. The medium crossing, estimated at five hours, requires stamina and careful navigation at intersections. This is a walk through understated engineering: rather than one monumental work, it presents a network spread across the slope to carry water from wet uplands to communities throughout the municipality.