It became a running joke, this good-natured rivalry between Portugal and Spain, on Emerald Waterways’ Emerald Radiance. Luis, our Portuguese cruise director, was full of wisecracks and puns in his afternoon briefing as we cruised toward our easternmost port on the Douro River. We’d dock for the night at Vega de Terron, Spain, he told us, but there’s nothing to see, just one house and a coffee bar. Don’t bother.
Indeed, the border with Spain on the Douro wasn’t much to look at, just a couple of bridges and a government building where the sort of bureaucratic formalities at borders presumably take place. For our excursion to Salamanca, a two-hour drive into Spain, Luis said we’d need to take our passports with us, joking that the Spanish authorities can’t be cajoled if one of us gets into trouble. No sense of humor. And Spain is in a different time zone, an hour ahead, Luis said, but we’ll keep to Portuguese time on the tour. More civilized.

No problem. Bill and I still use old-school wristwatches that don’t automatically update the time as our smartphones do. Looking around the sea of gray heads on our fellow passengers, I’m guessing we’re not alone. The age span among the 112 passengers on board seems to range from the late 20s to the 80s with a preponderance of baby boomers enjoying their retirement with a luxury cruise across Portugal. Emerald Waterways and its sister line, Scenic, are owned by an Australian and we did mingle with a few Aussies on board. Most passengers, though — I’m guessing 80 percent — hail from the UK. We counted just eight Americans, including us.

Two hours, even in Emerald’s comfortable motorcoaches, is a long time, but Salamanca proved worth it. Leaving the ship, we passed through a national park of brush-covered mountains and hamlets of 200 to 500 residents set among fields of olive and almond trees before the landscape transitioned to a high plateau of dry grasslands and sunflower fields. Suddenly, the church spires of Salamanca appeared on the horizon. Nicknamed the “Golden City” for the tawny hue of the sandstone of its old buildings, it has two cathedrals. Its 12th-century Romanesque one was preserved and adjoins the “new” cathedral started in the 16th century in gothic style with a few baroque elements added by the time it was completed in the 18th century.
Rolling his eyes, Luis had told us that Spain won’t allow Portuguese guides to lead tours, so our Emerald escorts yielded to a local guide. She gave us an excellent 90-minute walking tour of the cathedrals and pointed out the art nouveau ironwork on balconies, the elaborately carved sandstone façade of the city’s first university, founded in 1218, and the public market where we sampled Spanish ham, cheese and olives. After the tour there was time for more exploring. Bill and I stopped at the Roman Bridge and the Museum of Art Nouveau and Art Deco before finding a sidewalk café for a ham sandwich and pan of paella with some beer and a fine Spanish Rioja.

Back on the bus, we joined most of the passengers in observing the time-honored Spanish tradition of siesta with a snooze. By the time we returned, the ship had repositioned to the Portugal side of the river and as we crossed the bridge our Emerald escort counted down our remaining time in Spain: five, four, three, two, one. Welcome back to Portugal!
After a lovely dinner with wine, a nice tempranillo from Spain, we climbed up to the sundeck and joined a British couple watching the sunset. Normally full of passengers on a sunny afternoon, we had the deck to ourselves. A sliver of silvery moon hung in the sky and the bridge, illuminated at night, shone in the dark river. It was a magical ending to a memorable day in Spain.