This year it is 20 years since Alex Garland first published his backpacker classic The Beach. You couldn’t get on a plane or lie on a beach without seeing copies of the book in your neighbours’ hands. It was reprinted 25 times in less than a year and the film rights were hot property. The book about seclusion and secret places was everywhere.

The Beach is a modern take on Conrad’s Heart of Darkness. The backpacker, Richard, meets an unhinged Scotsman going by the alias of Daffy Duck who gives him a hand-drawn map, with directions to a beautiful island with a hidden lagoon and beach, located in the Gulf of Thailand and inaccessible to tourists. Richard finds paradise, but he and his fellow travellers are locked in a constant battle to keep it to themselves.

There are many places that claim to be the inspiration for The Beach including the undeveloped Ang Thong national marine park near Koh Samui. But there is one place I kept hearing about that was the original inspiration for The Beach: The Sanctuary on Koh Phangan. Even its name has a Beach-like vibe.

One friend who was getting over a breakup went there for a week and ended up staying several months. The visit changed her life, she told me. “Get on a plane, do what it takes, just get over there,” she urged.

The Sanctuary is a hippie resort that specialises in yoga, spa treatments, detoxes and alternative therapies yet also offers a hedonistic, party-vibe if that’s what you want. Accommodation ranges from dorm rooms to self-contained air-conditioned bungalows , high up in the jungle hills.

Because it was paradise it was not easy to find. When the weather is wet you can pay a guy to take the sometimes-treacherous route inland though dense jungle to get to resort but, if it’s calm, you can arrive by sea.

I flew from Penang to Koh Samui and caught a boat to Haad Rin wharf, then scrambled down rocks with a suitcase, which got tossed on to a fishing boat, before we took off, away from the hectic beaches that are home to the full moon parties, and headed towards a string of beaches that sit at the start of steep hills, covered in jungle. We pulled in at Haad Tien, which is made up of three bays and is the home of The Sanctuary.

As soon I got off the boat, carrying my suitcase aloft as I waded though the water, I was greeted by managers Michael Doyle and Nolan Dalby.

Doyle has been on the island for almost 20 years. An Irishman, he lived and worked for a time in Australia as a psychiatric nurse before he went travelling around Asia and discovered “the beach”.

“The Sanctuary in the early days was a few hippies on the beach,” he says. “It started as a communal thing 20 years ago. Ten to 15 years ago they built the wellness centre. Conscious, colourful party people come here.”

Each year more dorms and bungalows are added to accommodate the growing word-of-mouth crowds but costs are kept down, which results in an eclectic mix of budgeting backpackers and older, monied travellers having a week or two off from their banking jobs.

The Sanctuary easily fits the description of paradise. And not just because it’s devastatingly pretty with an azure bay circled by palm trees. It’s paradise because it operates like a community but without the boring chores like cleaning, cooking and governance.

The community aspect is strengthened by the fact that many people aren’t just passing through on their way somewhere else – it’s one of those places where people come for a week and stay for months or, in some cases, years.

“There’s a current between here and Bali,” says Dalby, who co-manages the property. “A number of yoga teachers and healers go between the two. We find people changing their flights all the time. There have been people who get to the airport on the boat and they turn around and come back.”

One Irish guest, Anne-Marie, loved it so much she moved into the bay area permanently. “One of the most beautiful things I find is that people really bond,” she says. “You see guests at the start and they are quiet and nervous and then they might do something like a course or a fast – and get great support from the others doing it – and they are friends for life.”

Dalby adds: “People become friends then come back with each other. That’s prevalent on the island – people work hard and then come back for six months and chill.”

The Sanctuary is a good balance between hedonistic and healthy. There is a fasting centre that sits down near the beach and is run by a man who goes by the name Mr Moon. The fasters sit in lounges away from the main bar and drink their special detox drinks at regular intervals. Not far away is the main bar and restaurant, which is the hub of the community. I am feasting not fasting and each day enjoyed pad Thai or seafood curry served in a coconut.

Doyle tells me about the parties every Friday night on another part of the island. “You go and just connect.” He takes his two peace fingers and point them at me – “connect”.

“On drugs?” No, not drugs here, he assures me – through the eyes you have a connection with people.

At first, I spend time alone in my room, high up in the hills with a balcony overlooking the bay, or reading the Bangkok Post in the restaurant, eavesdropping and scribbling in my journal.

But I soon find my way to the healing centre where you can put your name down to sample various new age therapies. I signed up for an “ecstatic dance” and at dusk I make my way along the trail to the hall. There were about eight of us and we sit in a circle, with Patrick as our guide. He is Australian – from a small town outside Sydney – and has hair so blond it is almost white. He wears those Thai fisherman’s pants with the complicated knotting at the front and more billows than a bagpipe yet he carries it off. He has a sort of regal bearing.

“I take people into the jungle and we do ancestral movement and games,” he explains. “Everything in the jungle speaks to us. I’m interested in rewilding the human being.”

Patrick has mixed up a drink containing cacao, a chocolate plant that is one of the most revered of the ancient Mayan deities. Music plays. He passes around the drink and we are asked to state what we are grateful for. There were several fasters in the group whose gratitude seems deeper and more profound than the gratitude of the eaters, who say things such as, “I am grateful to be here.”

The fasters are grateful not just for being here, but also for being. In the darkened hall, the whites of their eyes are illuminated as though they are wearing Halloween contact lenses. Their number includes a monk, an MBA student, a hypnotist, a lawyer and a traveller who had previously worked in the arts and culture sector in Darwin.

In the next 90 minutes I dance “ecstatically”, starting with Polynesian-style movements and clapping, followed by call and response and then just free-form dancing, until I am dripping with sweat. Massive Attack brings everyone down, then Patrick plays African drums and guitar and then a flute and we all lie on yoga mats. The candles around the room burn and the jungle makes noises and it is incredibly great and peaceful and then there is a tape of an Indian voice saying, “Be grateful for everything,” and for a few long minutes I am.

The wellness centre stocks plentiful detox books locked in a cabinet that smells musty. The first book I pull out looked old and is filled with diagrams of intestines. I flick it open to a part about impacted faeces – the stuff that hangs around in your gut – for, like, ever. Fasting and detox – together with colonics – is the only way to clean it out, apparently, and The Sanctuary offers it all.

Throughout the week I feast on delicious hand-made rice paper rolls with prawns, huge chunks of grilled salmon with soba noodles, coconut-battered fried fish with jasmine rice and green curry sauce, fish cakes, fried spring rolls filled with vegetables and prawns, ice-cold Singa served in stubby holders, smoothies and juices, fresh coconuts, cocktails, and fresh ginger, lemon and honey tea.

Dalby tells me that their regular visitors tend to alternate – they’ll come and enjoy the yummy food and the next visit they’ll do a detox.

We’ll see.

Bookable accommodation prices start at A$95 a night. Guardian Australia was a guest of The Sanctuary