By PAUL AMES

Cabanas, Portugal

T he fortress of Sāo Joāo da Barra was built to deter Spanish raiders and Barbary pirates from attacking Portugal's southern coast. Three hundred and fifty years later, its sturdy defenses continue to overlook the still, blue waters of the Ria Formosa lagoon and the narrow bar of white sand holding back the Atlantic beyond.

These days, however, there's a swimming pool built into the bulwarks, the walls are topped by sun decks and a palm-shaded breakfast terrace, and the lookouts patrolling the ramparts are lucky guests relaxing in this romantic retreat. Opened in 2007, the family-run Forte Sāo Joāo da Barra is part of a small but growing band of hotels running countercurrent to the wave of mass tourism that has swept over much of the Algarve region during the past 40 years.

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Forte De Sao Joao Da Barra

Aerial view of Forte De Sāo Joāo da Barra

Away from the rows of soulless modern hotel blocks concentrated in the central strip of the Algarve coast, canny visitors can stay in an isolated hilltop farmstead or Belle Époque spa resort; a restored rococo palace or a merchant's house overlooking the whitewashed streets of a medieval town center.

These hideaways make great bases to discover the delights of this sun-kissed stretch of southern Portugal where, if you know where to look, it's still possible to find deserted beaches, dramatic coastal scenery and simple village restaurants serving some of Europe's best seafood.

Autumn and spring can be the best times to visit when the summer crowds have evaporated despite average temperatures that linger in the low 20s Celsius. Golfers have the additional attraction of 35 courses strung along the 150-kilometer south coast.

Maria Sottomayor opened the fortress as a luxury 10-room bed-and-breakfast in 2007 in what had been a family vacation home. The old coach house and the army's gunpowder store were turned into suites, the chapel is a cool vaulted breakfast room and a row of rooms has been built on the site of the barracks in a stripped-down modern style, but using brick and granite that echo the fort's massive stone walls. Lounges and two guest rooms in the grand former governor's house are packed with antique furniture collected over the years by the Sottomayor family.

The star-shaped fort is reached down a dirt track running through olive groves and the imposing entrance is surrounded on the landward side by lush vegetation. "We're like a lost jungle city," jokes Ms. Sottomayor. However, a short waterside path runs into the village of Cabanas where the boardwalk is lined with restaurants like Pedro's and Noélia e Jerónimo which use locally caught seafood to serve up traditional meals like octopus fritters with cilantro rice, or white beans and whelks. The fort has its own boat to ferry guests over the lagoon to lonely spots on the beach.

Nearby Tavira is one of the best preserved coastal towns in southern Portugal. Elegant mansions line the left bank of the River Gilāo. On the other bank, narrow lanes lined with white-washed houses climb up to the medieval walls where Arabs and Christians once battled for control of the city. The river is crossed by an arched bridge said to date back to Roman times.

Paola Boragine fell in love with Tavira during a visit in 2001. The Italian architect has turned an early 19th-century townhouse into the Casa Beleza do Sul, a bed-and-breakfast which opened five years ago with two apartments and a suite on a side street close to the city center's cafés, boutiques and art galleries. Tropical plants fill the little patio and there's a terrace offering views over the riverside public gardens and the city's russet-tiled pyramid rooftops. "The aim has been to improve things only for comfort, but to keep as much of the original house as possible. The tiles may not be exactly level, but they are the originals," says Ms. Boragine, pointing to the intricately patterned Moorish-inspired ceramics on the floor of the Mosaic suite.

With soft natural fabrics, subtle lighting and traditional cane ceilings, Ms. Boragine has turned the old merchant's home into a relaxed, intimate space of pastel colors and airy spaces, that's popular with young families. Small boats moored on the riverside make the short trip across the Ria Formosa nature reserve to ferry visitors to an 11-kilometer-long beach island offering fine, white sand and calm, warm waters.

For a rather grander place to stay, head up the hillside to the Pousada Convento da Graça, a 16th-century convent that opened as a luxury, 36-room hotel in 2006. Inside its mustard-hued-walls is an island of otherworldly tranquility. Breakfast is served under the arches of a Renaissance cloister, a monumental stone stairway leads up to the rooms which are furnished with marble and hardwood and decorated with a mix of contemporary artworks and traditional tapestries and artifacts. A fresh breeze cools the garden out back where a pool lays in the lee of Tavira's ancient city walls.

While the region's south coast is famed for its sheltered coves and gently sloping strands, the western beaches can be rough and windswept with broad swathes of surf-battered sand wedged between precipitous black cliffs.

North of the fortress at Sagres, where Henry the Navigator planned Portugal's voyages of discovery in the 15th century, the seaboard is little touched by tourist development, but it's long been a favorite of surfers, nature lovers and seekers of solitude.

Once a globe-trotting TV presenter and stalwart of Lisbon's frenetic nightlife, Henrique Balsemão moved to this remote coast to convert a traditional hilltop farmhouse into a hippy-chic hideaway in the heart of the Costa Vicentina natural park. Visitors arrive along a series of country roads and a dusty trail that leads through a scrubland scented with wild thyme and lavender.

Opened in 2001, the resort has 12 suites spread through the single-story farm buildings. Each has a wooden deck, hung with hammocks for dozing through lazy afternoons where the silence is broken only by the eternal chirping of crickets. Adobe walls are painted in traditional blues and whites, local clay tiles cover the floors and the whole place is decorated with colorful modern art works and handicraft which Mr. Balsemão and his wife have collected on globetrotting trips—Moroccan rugs, rainbow-striped fabrics from the Caribbean and an elephant-headed Hindu shrine dominating the breakfast room. TV and Internet are banished, but activities to distract webaholics from a painful withdrawal range from yoga classes to horseback riding, mountain biking or, for the really adventurous, donkey treks. A new addition is a second-floor spa, with sauna and a massage room with a 360° view of the unspoiled countryside With nothing but ocean between this coast and Virginia, sunsets can be stunning.

The spectacular surfing beaches of Amado and Bordeira are a five-minute drive (or slightly longer donkey ride) away and there are fine seafood restaurants nearby like A Lareira in Aljezur, A Eiro do Mel in Vila do Bispo or A Tasca overlooking the fishing harbor in Sagres.

Like the Algarve's west coast, the rounded, scrub- and forest- covered hills of the interior are also little touched by mass tourism. The tiny highland village of Caldas de Monchique has however attracted a steady stream of visitors for centuries. The Romans are believed to have been the first to discover the benefits of the thermal springs at Caldas and in 1636 the bishop of the Algarve built bath houses here where the local clergy came to take health-giving the waters.

By the time King Carlos passed through in 1897, Caldas had become a spa for the smart set, complete with hotels, restaurants and a casino built in the fashionable Moorish-revival style. After decades of neglect, a philanthropic foundation took over much of the village and reopened it in 2001 as the revitalized Villa Termal Spa Resort.

Thanks to the abundant water the slopes are covered with luxuriant, almost tropical vegetation. There are more than 1,000 plant species including fragrant fig and eucalyptus trees, pines, chestnuts and Europe's largest magnolia. The resort comprises five small hotels. Oddly enough, the most popular is undoubtedly the ugliest, a bland 1960s block which houses the hot tubs, steam rooms and treatment rooms where you can be coated in chocolate, wrapped in mud, bathed in milk or simply soak in the mineral rich spring water.

The other hotels are all a short walk from the spa and offer more old-world charm. Pick of the pack is the Hotel Central, restored to its turn-of-the-century splendor with a colonial feel that recalls the coffee fazendas which the Portuguese built in Brazil and São Tomé. Rooms overlook the Esplanada dos Ulmeiros, a plaza shaded by venerable elm trees which is the perfect place to kick back with a bica (Portugal's potent version of espresso), a shot of medronho (the local firewater made from the fruit of the strawberry tree) or the sweat-sticky almond and cinnamon concoction known as a Dom Rodrigo.

Where to stay:

Forte de São João da Barra

Sitio da Fortaleza

8800-595 Cabanas de Tavira

Portugal

+351 281 370 495

Bed and Breakfast from €150

www.fortesaojoaodabarra.com

Casa Beleza do Sul

Rua Dr. Parreira 43

8800-346 Tavira

Portugal

+351 281 326 728

Rooms from €50

http://casabelezadosul.com

Pousada de Tavira Convento da Graça

Rua D. Paio Peres Correia

8800-407 Tavira

+351 281 329 040

Rooms from €150

www.pousadas.pt/historicalhotels/EN/pousadas/Portugal/Algarve/ConventodaGraca/home/PousadaConventodaGraca_Home.htm

Pousada de Faro Palácio de Estoi

Rua São José

Estoi

8005-465 Faro

Portugal

+351 289 990 150

Rooms from €200

www.pousadas.pt/historicalhotels/EN/pousadas/Portugal/Algarve/PalaciodeEstoi/home/

Herdade de Monte Velho

Carrapateira

8670-230 Aljezur

Portugal

+351 282 973 207

Bed and Breakfast from €100

www.montevelhoecoresort.com

Villa Termal das Caldas de Monchique

Caldas de Monchique

8550-232 Monchique

Portugal

+351 282 910 910

Bed and Breakfast from €65

www.monchiquetermas.com

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