The greens. The greens. The greens. If you want to know what will decide the 108th PGA Championship, look no further than the putting surfaces at Aronimink Golf Club. Turtlebacked, sloping, and merciless, these greens are the course's signature challenge—and they've been terrorizing golfers for nearly a century.

"The greens get really crazy," warned Keegan Bradley this week. "They are really mounded and hilly. I can think of several holes here where you can land it and be close to the flag, four or five feet, and it's going to roll."

Rory McIlroy echoed that sentiment, noting the strategic shift required. "It's a course where you can be super aggressive off the tee," he said, "and then there's a little more strategy and a little more thought going into the greens."

That lethal combination has been Aronimink's hallmark since legendary architect Donald Ross—the mastermind behind Pinehurst No. 2—built the course in its present location nearly a century ago. Named for a Lenape chief who allegedly lived on the property, Aronimink Golf Club traces its roots to the turn-of-the-century Belmont Golf Club, which itself broke off from the Belmont Cricket Club in 1896.

Officially incorporated by name in 1900, the club spent its first quarter-century moving westward from Philadelphia before settling in Newtown Square in 1928. That's when Ross arrived to work his Scotland links-inspired magic. "I intended to make this my masterpiece," Ross said in a famous 1948 quote you'll hear often this week, "but not until today did I realize I built it better than I knew."

Aronimink hosted its only previous men's major in 1962, when Gary Player claimed the PGA Championship. Photos from that week show a course and clubhouse remarkably similar to today's—minus the massive corporate hospitality tents. Now, more than six decades later, the world's best return to face the same relentless challenge: survive the greens, or watch your scorecard crumble.