Unique to championship golf, the historic layout in the suburbs of Philadelphia does not use flag-topped sticks to mark where the holes are and instead employs small oval-shaped baskets made out of wicker.
Looking for all the world like the punching bags used by boxers, they are painted red on the front nine and orange on the back.
They are eye-catching and peculiar and add to the quirky charm of the East Course, which was opened in 1912, but helpful to golfers they most certainly are not.
Flag-topped pins have the advantage of flapping in the prevailing wind and lending valuable insight to what shot needs to be played.
No such help comes form the stubbornly stoic wicker baskets.
Lee Trevino, one of four players to have won the US Open at Merion's East Course, in 1971 when he defeated Jack Nicklaus in an 18-hole playoff, recently summed up the problem they pose.
"I thought they were the most amazing thing," Trevino, now 73, said.
"They actually affect the way you play, because you always rely on the flag to tell you which way the wind is blowing.
"The wicker baskets tell you nothing."
How the baskets came to be used at Merion remains unclear with the club's website stating that the origin of the baskets "is a mystery to this day."
One theory has it that they were the brainchild of the course's designer, Hugh Irvine Wilson, a Scottish immigrant who returned to his homeland for inspiration and liked the look of shepherds' staffs while on his scouting trip.
More likely, though, was that at that time, such baskets were used at some British links courses to withstand seaside breezes and Wilson could have seen these, liked the look of them and brought the idea back with him to Philadelphia.
Whatever the origins, the baskets will confront a new generation of golfers this week as the last time the US Open was held at the course was in 1981 when David Graham became the first Australian to win the title.
Rory McIlroy, US Open champion at Congressional in 2011, encountered some modern-day technological problems right away when getting in some practice at the course last week.
He and his caddie found that the lasers they use to gauge distances to the holes for their yardage books would not register on the wicker baskets in the same way they did on flags.
"But I guess if it gets windy, you still know where the wind is, where the wind is blowing," said the Ulsterman, who at 24-years-old was not even born the last time the US Open was held at Merion.
"I guess it's just we're so used to looking up at the flagstick and seeing that it's blowing a certain direction and just for confirmation before you pull the trigger more than anything else.
"But you just have to commit and trust yourself and trust your caddie and trust that you've got the wind right."
Reigning champion Webb Simpson, who won at the Olympic Club in San Francisco last year, likes them even though he admits that most caddies detest them as it complicates their advisoory role.
For players, though, Simpson believes they can be more a help than a hindrance.
"I honestly think it will make us make decisions quicker," the American said.
"We're sitting there a lot of times and we see one flag over here blowing that way and a flag over here blowing that way and we get confused and second guess.
"We'll never play anything like this. So it's a once in a lifetime opportunity. It's just part of the tradition of Merion, part of the tradition of the club.
"When I was here in September they told me they were going to keep the wicker baskets and I was pretty excited about it."