DEER LAKE, PA.>> The rustic Pennsylvania training camp where Muhammad Ali prepared for some of his most famous fights has undergone an elaborate restoration, opening to the public Saturday as a shrine to the heavyweight icon’s life and career.

The famed Deer Lake camp was in disrepair when California real estate investor Mike Madden bought it shortly after Ali died in June 2016 at age 74. Madden, son of retired broadcaster and NFL Hall of Fame coach John Madden, said his aim was to save an important part of Ali’s legacy.

“It will always be a monument to the guy who created it,” said Madden, 55. “It’s about preserving a piece of sports history, American history and probably world history.”

Ali bought the wooded, out-of-the-way property about 90 miles (145 kilometers) from Philadelphia in 1972 and installed 18 primarily log buildings, including a gym, dining hall, small mosque, visitors’ cabins and a horse barn. It was at Deer Lake where Ali prepared for his epic bouts against George Foreman and Joe Frazier, attracting crowds who watched him work. Ali once proclaimed he was “more at home with my log cabins than I am in my house in Cherry Hill,” New Jersey.

He trained at the camp until his last fight in 1981.

“Ali loved it up there,” said his longtime business manager, Gene Kilroy, an area native who brought Ali to Deer Lake. “He built it the way he wanted to build it, and he credited that camp with helping him win his biggest fights.”

Ty Benner, whose father brought him to see Ali train every time he was at Deer Lake, returned Saturday for the first time in nearly 40 years, donating a T-shirt he got at the camp as a kid.

“My dad was a big Ali fan,” said Benner, 48, of Beaver Springs, which is about two hours away. “I pretty much grew up here.” He said Madden had done an “amazing” job restoring it.

Visiting from the Philadelphia area, Karen Hauck was also impressed. “I love this,” she said as her kids and their friend, 11-year-old Benny Quiles-Rosa, took turns at the heavy bag. Benny, an aspiring boxer, gave it quite a beating.

“I can’t wait till I’m allowed to spar,” he said. Seeing where Al trained, he said, “is a really big deal for me.”

By the time Madden bought the camp, the exteriors of the log buildings were deteriorating and needed extensive repair.

Inside, the gym sports a new ring and a sleek display of blown-up photos that show Ali living and working at the camp, slugging it out with opponents inside the ring and clowning around with other famous faces like The Beatles. A video retrospective of Ali’s career, narrated by Howard Cosell, plays on a flat screen, and some of Ali’s famous quotes (“Float like a butterfly, sting like a bee”) adorn the walls.

In an adjoining room, you can see where Ali kept track of his weight while training for a 1978 championship rematch with Leon Spinks. The actual notations are still there on the wall, in pencil.

Madden, a lifelong fight fan like his father, was listening to sports talk radio after Ali’s death and said he became supremely irritated by the misinformation he was hearing about his boyhood idol, whom he had met as a teen. It was the same when Madden turned to the internet — some of the stories about Ali’s life got the details wrong, he said. He stifled an impulse to comment.

Then Madden read a piece that mentioned Deer Lake, Googled it, and found out the camp was for sale.

“I literally had an ‘Animal House’ moment. I had an angel and a devil on my shoulders. Are you going to be the bitter guy who blogs anonymously when it comes to Ali? Every room you’re in, ‘They don’t have the story right.’ Are you going to be that guy?” Madden recalled thinking.

“Here’s an opportunity to have a hand in maybe not writing history, but preserving some,” he added. “I looked at it as a calling. This found me.”

Madden paid $520,000 for the property and spent at least $650,000 on renovations.

Other buildings open to the public include the mosque, dining hall and Ali’s sleeping quarters, complete with coal stove, hand-operated water pump and a video of Ali giving TV host Dick Cavett a tour of the same cabin 40 years ago.

The hilltop camp, dubbed “Fighter’s Heaven,” is open to the public on weekends. Admission is free, though visitors may donate to charities designated by the camp. It’s also available for corporate retreats.