"Church Pews bunker" is the name of a specific bunker at Oakmont Country Club
in Oakmont, Pa. The bunker is between the third and fourth fairways and is made up a vast expanse of sand broken up by a series of grassy islands that appear one after the other in a row. The name "Church Pews" comes from the berms' resemblance to rows of church pews.
For more, see the FAQ: What - and where - is the Church Pews bunker?