Analysis of information sources in references of the Wikipedia article "Par (score)" in English language version.
One was even recorded with a 3-iron! That one was made by Shaun Lynch, playing at Teign Valley Golf Club in Christow, England, in 1995, on the 496-yard No. 17. According to a 2004 article in Golf World magazine, Lynch aimed straight toward the green on a horseshoe par-5, clearing a 20-foot-high hedge, then hitting a downslope on the other side. The downslope carried his ball to the green and into the cup.
As noted, par-6 holes are rare, with most golf courses having only par-3, par-4 and par-5 holes. Most recreational golfers go their entire golfing careers without ever seeing a par 6.
According to The Guinness Book of World Records, the Satsuki golf course in Sano, Japan, boasts the longest hole in the world—an exhausting 964-yard, par-7 humdinger.