Piran

Tartini Square is the centre of everything: a wide oval of pale marble ringed by pastel buildings, once the inner harbour and filled in when it became a sanitation problem, now the town's living room. A Venetian Gothic house on one corner and the town hall face each other across it, and it is where the town eats, meets and holds everything it holds. From the square, lanes climb the slope to the cathedral of St George on its terrace, and the free-standing bell tower beside it can be climbed — a steep wooden internal staircase with open sides that is not for anyone uneasy about heights, and unquestionably the best view on the Slovenian coast at the top. Higher still, a section of the medieval town wall survives with towers you can walk along, and the view from there takes in the whole peninsula, the salt pans and Croatia beyond. Between these fixed points the pleasure is simply the street plan: narrow, shaded, occasionally passing under buildings, and preserved in its medieval form precisely because the peninsula was closed to traffic rather than widened for it. The transport guide covers where you actually leave the car and how the shuttle works, which is the practical half of the same decision.

Be clear about this before booking, because it determines whether the trip works. Piran has no sand. Its swimming is from concrete platforms and rock shelves along the western and southern shores, with ladders down into water that is clean, deep and clear immediately — which, for adult swimmers, is arguably better than shallow sand, and the sunsets from the western platforms are the reason people linger. For small children, for lying on a towel, or for a conventional beach day, it is not the right town. Twenty minutes around the bay, Portorož is where the coast's resort development went: imported sand, hotels with spas and pools, a promenade, thermal and salt-based wellness centres, a casino and a marina. The two towns are usually sold as one destination and they are not. If your trip is about wandering a stone town, eating well and swimming off rocks, stay in Piran. If it is about a beach and a hotel with facilities, stay in Portorož and visit Piran for the evenings, which is when it is at its best anyway. Neither answer is wrong; being surprised by the answer is what ruins the week.

At the far south of the municipality, where the river meets the sea on the Croatian border, the Sečovlje salt pans spread across a flat landscape of shallow basins, channels and low white banks that has been producing salt since the Middle Ages and still does, by hand, seasonally. It is now also a nature park, and the combination is unusual: a working industrial landscape that is simultaneously one of the best birdwatching sites in this part of the Adriatic, with waders, flamingos in some seasons and a great deal of open sky. There is a museum in the pans reached on foot or by bicycle along the banks, and a wellness operation using the brine and mud. The food guide covers the salt itself as one of the country's protected products. Inland, the municipality climbs into low hills of olive groves and vineyards that are recognisably Istrian rather than Slovenian in feel, dotted with small stone villages — Padna and Nova Vas among them — where the pace is agricultural and the views run back down to the sea. This is the half of the municipality that day visitors never see, and it is where a hire car finally earns its keep on this coast.

The coast eats Istrian, which means it eats more or less Italian with local particularities: seafood simply grilled or fried, shellfish, hand-made pasta, truffles from the interior in autumn, olive oil from the hills behind the town, and the local Refošk and Malvazija to drink. The seafood restaurants along the western waterfront are the obvious choice and are perfectly good; the better value is usually a street or two inland. Evenings are the town's best hours — the day visitors leave, the square opens out, and the light on the water from the western platforms is the thing people remember. On timing, June and September are the sweet spot: warm sea, manageable crowds and comfortable walking temperatures. July and August are hot and busy, and the town is small enough to feel it. May and October are lovely and quiet with a sea that is swimmable at the edges of the season. Winter is genuinely atmospheric — empty lanes, dramatic weather, most things open because people live here — and the bora wind can be fierce, which is a real consideration for anyone planning to be out on the walls.