When Jed and Heather honeymooned in Portugal last June, the time they spent in the historic villages of Óbidos and Sintra was almost dream-like in its simplicity and out-of-time feeling. “I don’t even remember the names of the restaurants we visited,” Heather said. “We just roamed around and found little places with great food.”

For their fifth anniversary last year, Danielle and Aaron flew into Porto in the northern part of the country, where they rented a car for a long weekend of exploring the Douro Valley. One of Portugal’s noted wine regions, the valley is home to exclusive resorts and spas nestled amid the dense, green mountains and hilly vineyard terrain.

Both couples — well-traveled young professionals who could afford to go almost anywhere — chose Portugal for the same reasons: exceptional food and wine, romantic places to stay, excellent value and the relatively short flight from their home airports on the U.S. East Coast. They were among thousands of U.S visitors who are helping, unintentionally perhaps, to bolster Portugal’s tourism industry — a welcome boost to the country’s fragile economy.

Portugal’s magnificent scenery, low crime rate and Michelin-star restaurants, in addition to a plethora of historic, government-run pousadas, have attracted millions of new visitors to the country in recent years. Perhaps adding to the lure for young couples, several TV segments of ABC’s The Bachelorette were filmed in Portugal. Plus, the 2010 Sports Illustrated Swimsuit Edition and a recent J. Crew catalog were shot on location here.

The European Travel Commission estimated a 4.1 percent increase in tourism to Portugal in 2010, when 29 new hotels — most with four or five stars — opened throughout the country. Currently, the tourism industry accounts for 5 percent of Portugal’s gross domestic product. Its capital, Lisbon, is Europe’s second-most-visited city, after Barcelona.

In the 15th and 16th centuries, hundreds of Portuguese explorers — Vasco da Gama, Ferdinand Magellan and Bartolomeu Dias among them — set sail from Portugal on a quest for wealth, power and prestige. Five hundred years later, a reverse voyage is taking place as modern-day explorers arrive in Portugal, seduced not only by its spectacular geography but by the friendly and generous Portuguese people.

In recent years, the Tourist Office of Portugal has noted a trend among incoming visitors: Many are young couples who view Portugal as an affordable destination for a honeymoon or a romantic weekend. Most couples head straight for the Algarve region in the south where white-sand beaches and picturesque fishing towns dot the landscape, but other areas are gaining in popularity, especially Estremadura north of Lisbon, Beira Litoral in the central interior and the Douro region in the north.

Just outside of Lisbon, Sintra is easily accessible by rental car or train. It is a small town brimming with romance, perfect for starry-eyed honeymooners and tried-and-true couples looking to rekindle that old honeymoon spark. Portuguese royal families used to vacation here. The Moors built a castle that overlooks the village, and 18th-century houses and inns were designed in the European romantic style. It is no wonder that Sintra’s entire historic center, Vila Velha, is a UNESCO World Heritage site.

The National Palace of Sintra, occupied since the 13th century, houses a collection of medieval azulejos (painted ceramic tiles) well worth the visit. There are numerous other palaces, monasteries and museums in Sintra, but just meandering around the old town — perhaps stopping for lunch or a drink at a local restaurant or bar — is a better way to experience the charm and beauty of this popular destination.

A one- to two-hour drive north of Sintra (depending upon whether you take the faster inland highway or the slower but more scenic coastal road along the Atlantic) leads to Óbidos. Located just 15 miles from the coast, the walled town — perhaps Portugal’s most photogenic village — and its surrounding territory was a belated wedding gift from King Dom Dinis to his wife, Dona Isabel, in 1228.

The idyllic town of just 11,000 residents offers upscale hotels and restaurants in addition to real estate prices only a king could afford. Wonderfully preserved, Óbidos attracts visitors who come to view the adorable white houses with blue and yellow trim, all surrounded by sweet-smelling flowers and vines. In the evening, after the mass-market tour buses depart, the setting sun infuses the sky with gold and crimson. Even the air becomes an aphrodisiac as couples stroll the town’s narrow lanes, perhaps stopping for tapas and wine at Bar Lagar da Mouraria, where beamed ceilings and stone floors serve to enhance the romantic atmosphere.

The journey from Óbidos to Coimbra in Portugal’s Beira Litoral region can be accomplished in less than two hours. But why rush when a leisurely drive with stops along the way includes lovely beach time near the quiet village of Foz do Arelho? More active couples may choose to crank it up a notch and head straight for Escola de Vela da Lagoa, a sailing and windsurfing school that also rents equipment.

Coimbra is a city of romantic accommodations and charming streets that wind up and around its numerous hills. It is also a university city, which means there are lots of cool bars, cafés and music clubs. Coimbra was Portugal’s capital in the 12th and 13th centuries, and the university was founded in 1290; so there are plenty of Romanesque and Gothic buildings, convents and churches to explore. For late-night partying, check out the ambience and architecture at Café Santa Cruz (Praca 8 de Maio), the music and art at Bar Quebra Costas (Rua Quebra Costas 45-49) and the lively outdoor patio and student crowd at Café Tropical (Praca da Republica).

About an hour north of Coimbra is Porto. Portugal’s second-largest city is a cosmopolitan center dating back a thousand years. Its historic district, Ribeira, along the Douro River, was a trading center in the 17th century, when boats carried barrels of Port wine down the river from the terraced vineyards in the mountains east of the city to ships in Porto’s Atlantic Ocean harbor.

Today, well-paved roads take visitors from Porto eastward into the Douro River Valley in one to two hours, passing well-tended quintas (wineries) that offer tours and tastings and through small villages where gourmet restaurants and high-end inns and spa resorts are now part of the landscape. There are also 12th-century monasteries and 18th-century palaces, one of which has been converted into an excellent art museum, the Museu de Lamego.

The Douro Valley, with its home-grown wine, excellent cheeses, smoked sausages and ham and fresh cod, is becoming renowned as a culinary tourism trail — one of dozens of roads to romance across Portugal’s countryside.

Info To Go

Lisbon Portela International Airport (LIS) and Porto Francisco Sa Carneiro (OPO) are Portugal’s main international gateways. buses serve Lisbon’s airport ($4.75, 40 minutes to city center). Passengers arriving at Porto can use the modern Metro Violet Line ($1.90, 25 minutes to city center). Both airports have taxis and car rental outlets. Visit www.visitportugal.com.

Lodging

Aquapura Douro Valley
This restored 19th-century manor house along the Douro River includes 50 deluxe guestrooms, 21 private villas, a spa and a gourmet restaurant. Rates include buffet breakfast. Quinta do Vale Abraao, Lamego, tel 351 254 660 600, $$$$

Hotel Quinta das Lágrimas
The legendary site of a prince’s forbidden love affair offers spa, garden or palace accommodations; botanical gardens; a spa and a Michelin-star restaurant. Rua Antonio Augusto Goncalves, Coimbra, tel 351 239 802 380, $$$$

Pousada de Óbidos
Situated within a 16th-century castle, this historic and romantic property offers nine guestrooms and modern amenities in one of Portugal’s most picturesque villages. Paco Real, tel 351 262 955 080, $$$

Dining

Arcadas da Capela
Chef Lourenço earned his Michelin star with food highlighting ingredients from the hotel’s garden and fresh fish from the coast. The lobster risotto is excellent. Hotel Quinta das Lágrimas, Rua Antonio Augusto Goncalves, Coimbra, tel 351 239 802 380, $$$$

Cantinho de São Pedro
Get your fill of Portuguese cuisine and plenty of fresh fish just a five-minute drive or 20-minute walk from Sintra; dinner reservations recommended. Praça Dom Fernando II, 18, tel 351 219 230 267 $$$

Quinta Romaneira
This Douro River resort estate is pricey but worth visiting for an ultra-romantic experience. Chef Miguel Castro creates memorable Portuguese and French-inspired menus. Cotas, Douro, tel 351 254 732 432, $$$$