My surreal encounter with Teshima Art Museum starts one sunny day in western Japan, as I approach the building, unsure of what I am seeing.

What is this huge white wavy structure? Who built an enormous igloo on a hill by the Seto Inland Sea and left it to melt into this elongated, elegant dome?

I enter it and its strangeness evaporates a little, though. The concrete space created by architect Ryue Nishizawa and artist Rei Naito has two oval openings in the ceiling and is empty, except for some water on the floor. Where is the art, I wonder, and did it rain in here during the typhoon the previous day?

But then I find the floor secreting a fat drop of water, fuller and rounder than any I have seen from a tap. More globules form. Moving like they have minds of their own, they gather and glide, like tadpoles and snakes, till they merge into ponds.

A fellow traveller, Wine & Dine editor Lin Weiwen, admits: "I thought of Terminator 2", referring to T-1000, the liquid metal shape-shifter from the 1991 movie.

The title of Naito's artwork is Matrix, a possible allusion to the mind-bending 1999 film.

I think we have wandered into a more serene sci-fi movie, though. Near us, a few elderly Japanese women are reacting with girlish glee or gentle bewilderment.

I venture into a circle of sunshine pouring in through one of the holes in the ceiling. Suddenly, the air seems to swoosh and the conversations around me sound like distant echoes - like I am listening to them from outer space. I must have a look of amazement on my face because one of the women is watching me with a wide smile.

Some other visitors sit close to the other round opening, perhaps to contemplate the sky, which looks like a pale blue egg and reminds me of the moon. Or maybe they are resting and waiting for the building to reveal another quiet wonder.

Teshima Art Museum is on the windswept island of Teshima in the Seto Inland Sea, which separates Shikoku, the smallest of Japan's four main islands, from Honshu, the largest.

I have come to Kagawa, a prefecture of Shikoku, to go island-hopping around the inland sea. Teshima and Naoshima have become hot spots of art tourism, thanks to a major push from Benesse Holdings, a Japanese company seeking to revive the remote islands with its affiliate, the Futatake Foundation. Teshima, Naoshima and other islands in the inland sea - including Inujima, Oshima, Shodoshima and Ogijima - also host the Setouchi Triennale once every three years. The next art festival starts in March next year.

Architecture, art and nature meet in remarkable ways at Benesse's projects, which include Teshima Art Museum and architect Tadao Ando's Naoshima museums for artists including Korean Lee Ufan and American James Turrell.

At Lee Ufan Museum, the sharp lines of Ando's building cut the surrounding expanse of greenery, creating dynamic shapes that set off the stillness of Lee's sculptures. One such image - a wedge of green hovering over a boulder - is so striking that I have to stop and sketch it in my notebook, following each line with my pen.

Ando's Chichu Art Museum is a marvel: It is a sequence of mostly underground structures acting as skylights, drawing sunshine deep into the basements to illuminate the art. And for one of the museum's most mesmerising installations, Turrell's Open Sky, the light itself is the canvas.

Working his magic through a square hole in the ceiling, Turrell has transformed the sky into a flat screen. One rainy day, I look up at the softly glowing screen and see clouds streaking across it like marble. But it is also a 3-D display, spilling raindrops that land on my face.

As avant-garde as the art may sound, it also seems traditional - of a piece with the Japanese practice of ingeniously using and improving on natural settings.

Behold the magnificent Ritsurin Garden in Takamatsu, the capital of Kagawa, for example. Dating back to the 17th century, the park is an intricately composed landscape of man-made hills, ponds, bridges, rocks and manicured foliage framing a grand view of Mount Shiun. In hotels such as Kotohira Onsen Kotosankaku (in Nakatado, a district of Kagawa) and the Bay Resort Hotel Shodoshima (on Shodoshima, an island in the inland sea), lush scenery is pretty much on tap. You get it in the lobby, in the room and through the picture window of the rooftop hot spring bath.

The art on Naoshima and Teshima does more, though. Some of it is not just beautiful and restful, but also playful, stimulating and powerful.

In Naoshima Bath "I Love Yu", a bathhouse created by artist Shinro Ohtake, I have to strip and shower to get to the art, which includes mosaics around and in a hot pool.

I am so determined to see every picture that three fellow bathers - all young Japanese women - cotton on and move away from the erotic woodblock prints and sexy posters on the floor of the pool.

Then I am excited and baffled by the bathhouse for days. What am I to make of the erotica on the floor, as well as an elephant statue in the room, stained glass windows, a hothouse and a ceiling covered in a rainbow of Magic Marker colours?

After visiting several tranquil spas on the trip - one zen space after another - the visual noise of Naoshima Bath "I Love Yu" makes sense to me. It is a maximalist getaway from the typical Japanese getaway, isn't it?

Benesse's businesses include education and eldercare, and two main markets - young and old people - are at the heart of its art projects. One of its objectives in starting the museums is to draw younger people to areas with ageing populations.

Accordingly, many of the projects are designed to be site-specific: This is not art that can be reduced to an image and enjoyed vicariously through Instagram on your smartphone. This is art you have to be there for and experience yourself.

Sure, such experiences can range from the sublime to the silly. Naoshima can feel like a goofy, arty playground, for instance, when you encounter Yellow And Black Boats by American artist Jennifer Bartlett at Benesse House Museum.

The artwork comprises three paintings of a coast and two boats placed under the paintings. Cutesily, two more boats have been placed on a shore visible from the museum as a mirror image of sorts.

But then there are real surprises, such as the instant you realise the tiny plants growing in the wall of the museum are naturalistic sculptures by artist Yoshihiro Suda.

Minamidera, a new house on an old site for a temple on Naoshima, may be the most emblematic of the island's experiential art projects. The building by Ando houses Backside Of The Moon, an artwork by Turrell, who is not as famous as he should be outside the art world, possibly because his light installations do not photograph well. His pieces have to be seen - and felt - in person.

(A gentle spoiler warning: If you hope to see Naoshima for yourself some day, you may wish to stop reading.)

In the case of Minamidera, it is pitch-black in the building and I have to feel my way in, one hand on the wall, step by step, with a dozen other visitors.

In the dark, we find a bench, sit down and wait - for we don't know what.

Minutes pass and I seem to see a white screen taking shape. An unstable rectangle with sides that waver, shrinking now and then back into the darkness.

Now a voice tells us the room has been dimly lit all along, although it took each of us some time to see it. When we are told to walk towards the light, we do so confidently, shrugging off all the uncertainty we felt just minutes ago.

The complete darkness we thought we were in isn't completely dark: It is a message that could have eased a believer's mind back when the site had a temple. It is a message Turrell and Ando have translated into an immersive experience that even an agnostic can draw comfort from now. I do.

The sky is grey and weepy when I leave the house later, yet my mood is buoyant.

The writer's trip was organised by Country Holidays.

Arty-crafty soya sauce

I had a bowl of rice one morning and it was so ineffably good that halfway through, I raced back to the hotel buffet and topped up my bowl: more rice, more raw fish pickled in soya sauce, more splashes of soya sauce.

I had three helpings of that rice, topped with that soya sauce, and I like to think I was puffing out clouds of soya perfume all day after that breakfast.

I was on Shodoshima, an island in the Seto Inland Sea that, as it transpires, is a base for traditional Japanese soya sauce production. Yamaroku Shoyu is one such brewery, where fifth-generation proprietor Yasuo Yamamoto persists with the methods of his forebears.

In his estimation, 99 per cent of soya sauce makers in Japan now use steel vats. Just 1 per cent still use wooden barrels and half of that 1 per cent are on Shodoshima, he says.

At Yamaroku Shoyu, blends of soya beans and wheat bubble slowly in man-size cedar barrels, some of which are more than 100 years old. The barrels stand in a storehouse that is at least 150 years old.

"No one is really sure how old this factory is," Mr Yamamoto says.

He and his staff sweep the floor of the storehouse, but never touch the mould on the beams, which is the source of the magic of natural fermentation.

The barrels have lasted so long that the barrel makers are going out of business.

In 2012, after the last barrel maker announced that it would close in 2020, Mr Yamamoto learnt to build his own barrels. He has assembled four since, using no glue and not one nail.

He worries that "true Japanese cuisine" is dying, as traditional soya sauce is fast disappearing. He has two sons and hopes they will keep the tradition alive, one brewing soya sauce and the other making barrels.

In the meantime, he jokes, he is influencing the boys and whispering "soya sauce, soya sauce" around them.