The answer is the 367-yard 11th at Merion Golf Club.
The plaque commemorates Bobby Jones winning the final leg of the Grand Slam in 1930 with an 8 & 7 victory over Eugene Homans in the U.S. Amateur.
The Baffling Brook lines three sides of the green and has presented numerous challenges for even the best of players.
There are wicker baskets atop the pins instead of flags.