IMPORTANT NOTE: The official arrows for the Coastal Route from Porto do not follow the river, but instead mirror the Central way for the first day of walking. This guide instead presumes that you wish to follow the water, and the description for doing so follows.
The easiest starting point for leaving the city is the Cathedral. With your back to its main door (facing west) pass the tower, keeping it on your right and follow the ramp downhill. Jog left then right around the building that is at the bottom of the ramp and then look to your left for a set of stairs that take you down to the plaza in front of the Church of São Lourenço (until the 1750’s a Jesuit Church, and thereafter it was purchased by the Order of Saint Augustine, at which time the church became known simply as Grilos).
With your back to this São Lourenço, take the left most street (Rua de Santa Ana) to the intersection with Rua da Bainharia and turn left. Mere meters later follow the curve of the road left onto the Rua dos Mercadores (going the wrong way downhill on this one way street). This narrow street will take you all the way down to the Cais da Ribeira, Porto’s waterfront.
Turn right at the water and from here you are to keep the river to your left, following the coast all the way to Matosinhos. The way is fairly straightforward but is not marked with arrows, simply keep to the road nearest the coast, the Rua Nova da Alfandega. In the distance you can see the Arrábida Bridge (the A6) which you will pass under, at which point you will have been following the waterfront for 3km. In another 2.5 you will reach the mouth of the river and the Atlantic Ocean, in the area known as Foz do Douro; Porto’s most affluent suburb and your first glimpse of sandy beaches.