On the edge of Rishikesh, in the foothills of the Himalayas, lies an overgrown ashram reminiscent of the great ruins of the Mayans.

Fifty years ago this year, the Beatles arrived at this unlikely location at the invitation of the Maharishi Mahesh Yogi.

The visit has passed into rock'n'roll legend even as the ashram has fallen into ruin. Much of the fabled White Album was composed in these now-derelict halls and bungalows.

Everything is crumbling, overgrown: the kitchen, the printing press, the post office where John Lennon waited for daily postcards from Yoko Ono even though he was travelling with his wife.

The "Beatles' Ashram", as it is colloquially known, serves as a humbling reminder that, as George Harrison once put it, "all things must pass". The line — the title of Harrison's first post-Beatles album — was cribbed from the Maharishi himself.

An abandoned accommodation building at the "Beatles' Ashram", Rishikesh. ( ABC News: Matthew Clayfield )

The ashram witnessed the birth of other classics too, such as Back in the USSR, Blackbird and Dear Prudence, the latter of which Lennon wrote to lure Mia Farrow's sister away from her seemingly non-stop meditation sessions.

"She'd been locked in for three weeks and wouldn't come out, trying to reach God quicker than anybody else," Lennon told Rolling Stone.

"That was the competition in Maharishi's camp: who was going to get cosmic first."

A mural-covered meditation hut on the rooftop terrace of the accommodation building at the "Beatles' Ashram". ( ABC News: Matthew Clayfield )

'Waves of joy are drifting through my opened mind'

Dehradun-based journalist Raju Gusain has become something of an expert on the Beatles' time in Rishikesh and the decades that followed at the Chaurasi Kutia ashram.

Dehradun-based journalist Raju Gusain helped revive the story of the Beatles' visit to Rishikesh. ( ABC News: Matthew Clayfield )

"Whenever anybody is keen to learn about the ashram, I like to come and help them explore," he says, sitting outside the ashram's bare-bones cafe in the old administrative building.

The Maharishi's lease on the ashram's land expired in 1981 and the yogi decamped to the Netherlands in 1992. But certain followers remained until the early 2000s, when India's Supreme Court ordered them to leave.

"The political situation in the country did not favour the spread of the Maharishi's knowledge," says Anand Srivastava, the Maharishi's nephew.

"No one can feel happy about having to leave the place where an entire movement took shape. We would have definitely preferred to stay."

The land was designated part of the Rajaji Tiger Reserve.

Nature reclaimed what the looters left behind, wild elephants did their share of damage, and the rot began to set in.

Music fans would occasionally find their way in, brandishing sharpies and writing lyrics on the walls, and local lovers would sneak in to canoodle away from prying eyes.

An artwork by Pan Trinity Das in the "Beatles' Cathedral Gallery" at the "Beatles' Ashram", Rishikesh. ( ABC News: Matthew Clayfield )

"Nobody knew much about the Beatles' visit when the Maharishi's people left," Gusain says.

"I began to collect newspaper clippings and photographs and started writing about the ashram's history in the newspaper."

People became interested in the story.

"Ultimately, the government saw the ashram's tourism potential and reopened it two years ago," Gusain says.

Which is to say they reopened the gates and started charging an entrance fee. Until February this year, when two small exhibitions were unveiled, little was done to develop the site as a tourist attraction.

One of these exhibitions details the "scientific benefits" of the Maharishi's patented Transcendental Meditation program. The other shows photographs of the Beatles and their sizeable entourage, including the Scottish singer-songwriter Donovan, the Farrow sisters, and the Beach Boys' Mike Love.

The photos were taken by Paul Saltzman, who joined them at the ashram. His book, The Beatles in India, was released in February and his film of the same name will be released later this year.

Photographer Paul Saltzman with Ringo Starr. Saltzman's photographs of The Beatles are the subject of his new book, The Beatles in India. ( Insight Editions: Paul Saltzman )

The shift in focus is already having an effect: 2,060 foreigners visited the ashram in the first four months of this year, compared with 181 in all of 2015.

The Maharishi's people find this disturbing.

"We have no prejudice against the Beatles and have always had very good relations with them, but calling this place the 'Beatles' Ashram' downgrades its value," says Mr Srivastava.

And the changes are only beginning.

Meditation huts on the grounds of the "Beatles' Ashram", Rishikesh. ( ABC News: Matthew Clayfield )

'Words are flowing out like endless rain into a paper cup'

The Beatles' time at the ashram would prove to be the most productive song-writing period in the band's short history. Between hanging out with the Maharishi and meditating, they wrote roughly 40 songs in seven weeks.

Even Ringo wrote something here, despite leaving after only 10 days. (He didn't think much of Indian food and his wife couldn't handle the bugs.)

But it wasn't all music and mantras. The trip did little to ease the tensions that were already beginning to tear the band apart. At one point, Harrison complained there was too much song-writing going on.

"We're not f***ing here to do the next album, we're here to meditate!" McCartney recalled him complaining.

The Maharishi Mahesh Yogi in 1967. ( Nationaal Archief: Ben Merk (CC:BY) )

The trip ended acrimoniously, with the Western contingent, spearheaded by Lennon, accusing the Maharishi of sexual impropriety against Mia Farrow and others. Lennon would later write the song Maharishi in revenge, which Harrison pleaded with him to rename Sexy Sadie:

"Sexy Sadie you'll get yours yet / However big you think you are."

The Maharishi, who died in 2008, always denied the claims, insisting he asked the band to leave as drugs and alcohol were being consumed in the compound. (In her memoirs, Cynthia Lennon admitted some of the group had indeed been smuggling in "hooch".)

Harrison would later reconcile with the guru, and McCartney and Ringo appeared at a function promoting Transcendental Meditation in 2009, but Lennon spoke with contempt for the Maharishi for the remainder of his life.

Like most Indians in Rishikesh, Gusain believes the Maharishi's story, but says it doesn't matter either way.

"The Beatles' visit ended badly," he says, "but that didn't stop it from changing everything".

In 1968, Rishikesh was a small town on the Ganges with a tourism industry best described as non-existent. Today, more than 40,000 tourists visit annually. Most are here for a taste of the Eastern spirituality that the Beatles helped to popularise: the streets abound with advertisements for 200-hour yoga and meditation courses, reiki and healing sessions.

According to Gusain, the international success of the Maharishi and his various organisations — which estimates over the years have valued at between $US2 billion and $US5 billion — would not have been possible without the Beatles' influence.

No longer a "village", Rishikesh is a buzzing destination for spiritual-minded tourists. ( ABC News: Matthew Clayfield )

Yet the Beatles cottage industry is surprisingly small here. Beyond a few places named after the band and the occasional piece of street art, there is little to suggest their connection to the place.

One of the few exceptions is Beatles' Choice, a gemstone and souvenir store not far from the river.

"My grandfather owned a clothing store where the Beatles and their friends bought their clothes," says store owner Mohit Ganeriwala, who decided to capitalise on the connection when he struck out on his own.

"They could have gone somewhere else, but they chose my family's store.

Mohit Ganeriwala, owner of Beatles' Choice, shows off a photo of John Lennon and Paul McCartney taken by his grandfather. ( ABC News: Matthew Clayfield )

"He met them several times, but he was much more impressed by the Maharishi and his people, who were also regular customers. People didn't really know who the Beatles were.

"They only knew they were important from the media people following them."

Mr Ganeriwala says his grandfather regularly spoke about how much Rishikesh had changed since the days when it was "just a village".

"As yoga has become more popular overseas, everyone here has become a yoga teacher," he says.

"They might not know yoga, but they know they can make money off it."

Rohan Ranjan and Akshat Agarwal came specifically to the ashram to play the Beatles. ( ABC News: Matthew Clayfield )

'Nothing's gonna change my world'

But while spirituality draws in most, the Beatles still call out to some.

Akshat Agarwal and Rohan Ranjan are musicians in their mid-20s who have come to Rishikesh specifically to visit the "Beatles' Ashram".

They've been playing Norwegian Wood in the "Beatles' Cathedral Gallery", an old yoga hall that Canadian street artist Pan Trinity Das has decorated with murals of the Beatles and the Maharishi.

"We've heard all the Beatles' songs," Mr Agarwhal says.

"We've performed a lot of them with our friends. They're very important to us."

The dilapidated hallways of an abandoned accommodation building in the ashram. ( ABC News: Matthew Clayfield )

They're a little surprised by what they've found at the ashram.

"It's not at all maintained," Mr Ranjan says.

"They have all these meditation rooms and private residences and if they had been maintained a lot of people would have come and stayed here."

In 2017, the Uttarakhand Forest Department announced a $20 million renovation for the ashram, including a souvenir store and educational areas.

"We plan to develop Chaurasi Kutia as an eco-tourism centre," says Sanatan Sonker, director of the Rajaji Tiger Reserve.

"Our aim is to link the ashram with local villagers and help them earn their livelihood through tourism."

The Forest Department has said none of the existing infrastructure will be adversely affected. Das' artworks will survive, as will two decades' worth of visitors' thoughtful graffiti.

Mr Srivastava, who spearheads the Maharishi Group of Companies, would prefer they didn't.

"The graffiti related to the Beatles definitely doesn't gel with Vedic knowledge, including yoga and Transcendental Meditation," he says.

"People may be curious about the Beatles, but they need to appreciate the force that brought them to this place. We would like the ashram to regain its glory as the springhead of knowledge."

Lucile Formica (left) and Florent Panfili in an old yoga hall. ( ABC News: Matthew Clayfield )

But tourists Florent Panfili and Lucile Formica aren't convinced anything needs changing. They sit on the ground of another old yoga hall, reached through a warren of isolated meditation chambers — the "84 caves" that give the ashram its Indian name.

A Das mural urging visitors to "Let It Be" almost glows in the sunlight. It might well be read as an exhortation to potential developers.

"I don't know why there's no museum or anything," Ms Formica says.

"But it's cool like this. It's the quietest place in town."

"I think it's meant to be like this."