As I wrote in a previous post, there’s no riight answer and there’s tons of debate about this on this forum. Depends on what you like, and maybe on where you’re from. Far more pilgrims on the central, and more of a pilgrim “vibe”, like on the Frances. More historical towns on the central. The coastal has fewer pilgrims, and less pilgrim infrastructure, but many find it beautiful with the ocean (almost) always within sight. We’re from coastal California, and perhaps for that reason, we found the coastal route rather monotonous, with dull, touristy beach towns, and nothing but pavement or boardwalks underfoot, so 2 days north of Porto, at Esposende, we decided to switch back to the central, and continued on from there. Overall, we found the central to be green and rolling, with more variation in scenery, and although there's plenty of pavement, it was less than on the coastal route.
The good thing is you don’t have to make up your mind until you’re in Porto, and even if you start on one, you can switch over to the other easily enough, with buses or taxis linking the towns along the two routes. Weather is also a factor. If the forecast is for warm, sunny weather, it will be cooler on the coast. If the forecast is for rain, you’ll have a cold wind off the ocean whipping your face on the coastal route, while on the central route you’ll be more sheltered.
I think Happymarkos may be a bit confusing above. The "seaside" route is also known as the Senda Litoral. The differences between it and the Coastal Route are minor, and often the two routes are the same. When they differ, it's generally that the Senda Liitoral will take you right along the sand, while the Coastal Route will be along a boardwalk or road flanking the beach -- in other words, often only 100 yards part. Both go through the same places, and you can skip back and forth between the two almost at will. If you get
Brierley's guidebook, the differences between all the routes will be clear.
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