Cascais sits at the end of the railway line from Lisbon, forty minutes along the coast, where the estuary of the Tagus opens into the Atlantic. It was a fishing village until the Portuguese royal family began spending summers here in the 1870s, and the exiled royals of half of Europe followed them in the twentieth century. Today it is the capital's seaside, polished and relaxed at once. Choosing linen for Cascais comes down to a handful of practical questions.

Is the water warm? Not especially. The Atlantic off Cascais is cool even in August, typically around seventeen to nineteen degrees Celsius, while the air on the town beaches can be well into the high twenties. That gap shapes the day: long hours on the sand and short, bracing swims. PP natural swim shorts in Vanille are the garment for those swims, and a shirt goes straight back on after.

What about the wind? North of town, Guincho beach faces the open ocean beneath the Sintra hills, and the Nortada, the summer north wind, often blows hard there in the afternoon. It is a place for surfers, kiters and long lunches at the seafood restaurants on the cliffs. Light linen that moves with the wind is more comfortable here than anything stiff. The Laos Long Sleeve Linen Shirt in Oyster, sleeves down when the breeze turns cool, is the shirt for Guincho; women will find the PP linen blouse in Lemon, with wide trousers, equally easy in moving air.

What does one wear in town? Cascais is a walking town of cobbled lanes, a citadel converted into a hotel and art spaces, a marina full of sailing yachts and a promenade that runs east along the sea to Estoril. The dress is casual and well kept. The PP Natural Set in Sky Blue, shirt and shorts cut from the same cloth, handles a day of walking, lunch on the harbour and an hour in the Casa das Histórias Paula Rego, the red pyramid-roofed museum. Sets of this kind are in the PP natural sets collection; the ladies linen set in Sky Blue is its counterpart in the women's collection.

And in the evening? Dinner in Cascais is a little more dressed. The restaurants of the old town and the terraces of the seafront hotels, the Casino Estoril a walk east along the promenade: none demand a jacket, but all reward care. The Vibes Linen Shirt in Dark Blue over PP Trousers 100% Linen in White is a sound answer. The Amelia linen dress shirt in Violet, with a cardigan for the walk home, is the women's equivalent.

Is Sintra a day trip? Yes, and it changes the wardrobe. The hills above Cascais trap mist and cool air, and the palaces of Pena and the Quinta da Regaleira are usually several degrees colder than the coast. A long-sleeved shirt and a light knit are enough. The road through the Sintra-Cascais Natural Park, past the lighthouse at Cabo da Roca, the westernmost point of mainland Europe, is one of the finest drives in Portugal.

Cascais has its own town wardrobe in the Journal, what to wear in Cascais, which follows the season month by month. South of the Tagus, the rice fields and dunes of Comporta ask for an even simpler version of the same clothes.

The PP collection is carried in resort boutiques at One&Only Aesthesis near Athens and One&Only Kéa Island, and at Tiziano Brunetto in Santa Margherita Ligure, on the Portofino coast. For those travelling the Atlantic shore of Europe, these are the nearest addresses where the shirts can be held; the others are in Dubai and Puerto Rico.

The town's bay faces south, which is why it shelters from the north wind that empties Guincho in the afternoon. The fishermen knew that long before the kings arrived.

Read more: What to Wear in Comporta  ·  What to Wear in the Algarve