Each day, the crew made the two-hour drive in a fleet of taxis to the location, a remote mountain village called Chinchero. There, Henry Jaglom remembers “the rooms were horrifying. They were these terrible little rooms… llamas could come through the door. They were shitting in the bathroom.”

Another problem was altitude sickness; Chinchero is 11,000 feet above sea level. Stockwell reckons “70 – 75 per cent of the crew got sick.” Stunt co-ordinator Chuck Bail recalls, “I watched [cinematographer] László Kovács walk up a little grade in the village, and when he got there, he fell flat on his face, didn’t even put his hands out in front of him.”

The altitude got the better of Henry Jaglom, who left the film after two weeks. In a journal entry dated January 26, 1970, he wrote: “My god, what a birthday. A llama in the kitchen. Up at 6am after 2 ½ hours’ sleep. Bodyaches. Chaos; can’t eat breakfast. Tea. Raining. Two-hour drive to the location along an unpaved, unmarked winding donkey track… I sit alone in a car while Peruvians try to dig me out…”

The shoot itself lasted for seven weeks. Despite having the full script co-written by Stewart Stern, Hopper opted instead to improvise much of the film on location.

“Oh, I’m not afraid to start work with an empty head,” he told Darrach. “If you can’t create out of the moment, you’re not creating.”

“He didn’t even make up his mind what I was going to do until we got down there,” says Stockwell. “There wasn’t a script. He’d outline it, and then we’d go do it. But he was absolutely in control. In his own inimitable way. At that time, he was a piece of work like nobody I’ve ever known. Dennis was all over the place, all constant energy, you just couldn’t shut him up for a second – he had more energy than 10 people. He was awesome to be around.”

“I call him an instinctive director,” adds Chuck Bail. “If he saw the sun going down, he’d yell at László Kovács. They’d immediately set something up to get that sunset through a stained glass window. As things go, that’s how he directs. He has a big plan in mind.”

Not everyone, however, was thrilled with the antics of a US film crew in the region. In an anonymous letter published in the Village Voice on December 24, 1970, one ex-pat wrote: “The absolute cultural insensitivity not only made me sick once again about my country and its fucked-up rich citizens, but have caused the government of Peru to crackdown on longhair tourists. The military [have] started mass shakedowns, round-ups, detentions, drug busts…”