"It's impossible to get to know the entire country, but we try to combine sightseeing with learning more and more about China. Our last trip was to Nanjing, for example, and although Portugal is full of beaches, the beach we go to most is Sanya on Hainan Island," said Petro.

While they both love exploring China, they have slightly different tastes. "I prefer smaller places, beautiful villages with traditional houses, but Pedro loves the big cities," said Graca.

Echoing Graca, Pedro said that Beijing is his favorite place.

"I have been (there) many times, twice in an official capacity, when I was in charge of the Air Force health service, and many times since to visit friends. For me, Beijing is the very essence of China. I like Shanghai, but there are places elsewhere in the world that are similar, whereas Beijing is unique," he said.

"But I also really like inland cities," Pedro continued, "especially Kunming, where you can go walking and the landscape is just amazing."

"I love Chinese painting and I always thought it was very imaginative, but then you go and see places like Kunming or Guilin and you realize it's actually highly realistic! The rocks are really like that, the trees are really like that! It's extraordinary," Petro said.

While Pedro has a passion for painting, Graca for food. She has written a book about the gastronomy of Macao and seeks to promote and preserve its traditions and encourage culinary authenticity.

"There isn't a specifically Macanese restaurant in Lisbon, but there are lots of Chinese ones nowadays and the food is very popular. Nevertheless, some people still think only in terms of sweet and sour pork!" Graca said.

"This is a shame because there is such great regional variety in the cuisine of north and south China, though I must admit, my favorite remains Cantonese," said Graca.

For Pedro, it's not just the food itself.

"It's the whole concept of eating lunch together or meeting for tea, because people in Portugal might go for lunch together, but they sit side by side, and it's not so easy to talk, whereas in a Chinese restaurant the table is round, which makes people more sociable," he said.

When Pedro first came to Lisbon, there was just one Chinese restaurant, but now there are many. Pedro believes it reflects broader shifts in interest and awareness.

"The interest in Chinese culture has increased hugely in Portugal in the last 40 years, and the kind of interest has changed too. It used to be the appeal of the exotic, but now it's a question of engaging with an established culture," he said.

Noting that China's status in the world has changed over the past 40 years, he said he believes that "China is now occupying its historic place."

"The number of conflicts in South Asia have reduced as China has grown, for example, and that's important. I think the role China is playing, not only in terms of China but the whole region, is remarkable," he added.