A large number of coastal resorts began as working harbours and became holiday towns in a recognisable sequence. Knowing that sequence tells a visitor where to look and where not to.
The harbour came first and fixed the site
Villages formed wherever a bay, headland or river mouth gave shelter to small boats. Everything else was arranged around the ability to land a catch safely.
Cottages were built close to the water and tightly packed, on steep ground if that was what the shelter required. The oldest core is therefore usually the most awkward and most attractive part of town.
Because the harbour dictated the location, resorts of this type often have a small, irregular centre attached to a much larger and more regular later town.
Rail arrivals changed the economics
The arrival of a railway made a distant coast reachable within a day, converting a fishing settlement into a destination for people with time and money.
Demand for accommodation followed immediately, and the response was terraces and hotels built along the seafront rather than around the harbour. The town's centre of gravity shifted.
This is why the grand seafront architecture in such towns is frequently of one period and the harbourside is of several. One grew slowly and the other was built to a plan.
The promenade is an engineering structure
Seafront walkways were built as coastal defence as much as amenity, holding a line against erosion and providing a hard edge behind which building could proceed.
Piers extended that logic outward, giving deep-water access and later becoming entertainment platforms in their own right.
Both required continuing maintenance, and the condition of a promenade is a reliable indicator of how a town's fortunes have run since it was built.
Fishing usually shrank rather than vanished
Quota systems, larger vessels and consolidation into major ports reduced small-harbour fleets substantially over the past several decades.
What survives is often a small working fleet alongside leisure moorings, with the harbour buildings converted to restaurants and galleries while the slipway still functions.
The mix is visible early in the morning, when the working side of the harbour operates and the tourist side has not opened.
The layout tells you where to stay
Seafront hotels have the view and the noise; the old core has the character and the hills; the later suburbs have parking and little else.
Restaurants cluster on the harbour because that is where visitors gather, but the ones locals use are frequently a street or two inland where rents are lower.
Reading a coastal town in these layers takes an hour of walking and is more useful than any list of recommendations written for a town whose centre keeps moving.