Sarah Marshall enjoys the best of food and wine in the beautiful north of Portugal.
Gliding slowly along the motionless Douro River, we slice through near-perfect reflections of undulating hills etched with vine terraces resembling contours on a map. Sandeman, Taylor's, Graham's - I pick out port producers whose bottles fill my drinks cabinet at home.
We're tracing a centuries-old route used to transport the Portuguese fortified wine to the coast; only these days, a flotilla of traditional rabelo boats carry tourists rather than heavy wooden casks.
The world's oldest regulated wine region, afforded Unesco World Heritage status in 2001, has been attracting river cruisers for many years, with land stays possible in a collection of simple quintas.
But in the past 12 months, the launch of two boutique hotels has broadened the Douro's appeal. Last summer, Six Senses announced a property in Lamego as their first European outpost and in April, the Taylor's Port family (now part of the Fladgate Partnership) re-opened Vintage House Hotel - a property they'd owned 10 years previously.
Coupled with the recent completion of a new mountain tunnel, which cuts journey time to gateway city Porto by 30 minutes to an hour and a half, this scenic wine lovers' region is ripe for visiting.
Our wooden boat docks at the small, sleepy village of Pinhao, famous for its azulejo-tiled train station depicting bucolic scenes of the wine harvest.
Several times a day, trains toot along the line, making a two-hour journey through the hills to Porto. From the waterfront, it's a hop, skip and port-addled stumble to the Vintage House Hotel, where swallows flit through orange trees and trellises are festooned with magenta bougainvillea.
"We've worked hard to retain features of the original warehouse building," explains General Manager Paulo Santos as we admire the gnarled oak beams of the Library Room supported by original granite columns.
Seven new suites have been added, bringing the number of rooms to 47, all with views to the river, and colour schemes have been brightened up a notch to bring the feeling of outside in.
I stay in one of the Master Suites, notable for its playful Christian Lacroix bathroom wallpaper and its size, which is bigger than most city apartments.
In the next couple of years, there are plans to build a spa and gym, but when dealing with a place this peaceful and protected, it's a respectful case of "slowly, slowly", explains Paulo.
The hotel's relaxed, rustic restaurant is a fine showcase for produce from the region, including lamb and veal reared in local hill villages, and peppery olive oil. But for a real taste of the Douro's liquid assets, I visit the Fladgate Partnership's neighbouring Quinta da Roeda wine estate, where a visitor centre is housed in the former stables.
Filipe Carvalho, Wine Tourism Manager, estimates there are 30,000 wine growers in the Douro Valley. Since the 18th century, land has been slowly consolidated and now British companies Taylors and Symington own 50 per cent of it.
In the past 20 years, many young winemakers have switched to making table wine. As well as being quicker and cheaper to produce, it's also winning the region top industry accolades.
Filipe is more of a traditionalist.
"We've been making port using the same methods for hundreds of years, although we do have a few innovations," he says, pouring an aperitif I soon identify as synonymous with summertime - a Croft Pink rose port and tonic on ice.
During harvest time, most work in the vineyards is done by hand - or foot. Filipe claims grapes trampled by humans taste far superior to those churned in cold stainless steel vats.
"It works out more expensive," he admits.
"But this is still a family business and social sustainability is more important than profit."
Adrian Bridge, CEO of Fladgate Partnership, and a member of the Taylor's family, envisages the Douro as a centre for wine tourism.
Six years ago, he opened Portugal's first wine hotel, the award-winning Yeatman, in Porto, and he hopes success will trickle along the river.
Set amid terracotta-roofed port warehouses in Vila Nova de Gaia, the elevated 82-room property gazes out across the mouth of the Douro to a piled-high stack of historic buildings that earned Porto Unesco classification.
Rooms are named after national winemakers, and corridors are decorated with vintage maps and paintings celebrating Portugal's place in the world of exploration and travel. Guests can cool off in an outdoor decanter-shaped swimming pool, and a staircase winding through an enormous wine barrel connects treatment rooms in the Caudalie Vinotherapie spa.
Appropriately, it also boasts the city's only Michelin-star restaurant. Sitting eye level with the clouds on a panoramic terrace, I enjoy Chef Ricardo Costa's sublime 10-course tasting menu while watching a tangerine sun melt into the Atlantic coastline as elegant peacocks strut around my feet.
Peanut-laced crabmeat served with a dash of beer and braised lime evokes days at the beach, and a tomato tartare sprayed with cool foam is a chillingly pleasant summer treat. The marathon meal is also an education in Portuguese wines, with my favourite, a Soalheiro Alvarinho 2014, served by the jeroboam.
Tourist attractions in Gaia revolve around the port cellars (all, apart from Taylor's, require an appointment), while most historic sites are on the opposite side of the river. The city is built on a series of hills with narrow, cobbled backstreets trailing from the tourist-packed riverside.
So the following morning, I take a scenic cable car (five euros, one way) to the double-decked, metal-arched Dom Luis bridge and cross the less busy upper level.
Blue and white azulejo tiles glint from the facades of grand, well-weathered buildings, with the most impressive display found in the concourse of the 1900s Sao Bento train station.
My favourite spot, though, is Livraria Lello, a bookshop said to have inspired Harry Potter's library at Hogwarts (author JK Rowling lived and taught English in Porto in the 1990s).
A fairy-tale crimson staircase spirals like a nautilus shell to reach a mezzanine floor and stained-glass skylight, which depicts a monogram belonging to original owners, the Lello brothers. It costs three euros to enter, redeemable on the purchase of books, which include rare editions from when the shop first opened in 1906.
There are numerous viewing platforms throughout the compact, crumbling city, and in the absence of skyscrapers, 18th century Torre dos Clerigos still occupies the highest point. There's a 25-minute queue to reach the top (visit early or late in the day to zip up quickly), where views stretch along the Douro. The sound of seagulls mewing is a reminder the ocean is close by.
A beacon for sailors, the tower also served as a telegraph, with flags hoisted to announce the imminent arrival of the English Royal Mail Lines carrying payment for port wines traded by merchants.
Today, though, the destination itself is the Douro's greatest commodity.
Further information: See visitportugal.com.
Sarah Marshall travelled as a guest of Classic Collection Holidays.