What Is a Bunker on a Golf Course?

Graham Marsh plays out of the Big Bertha bunker at Royal Portrush during a Senior British Open
This is the 'Big Bertha' bunker at Royal Portrush Golf Club in Ireland. Don't worry: Most bunkers aren't this big or this deep. David Cannon/Getty Images

A "bunker" is a golf course hazard that is a hole or depression in the ground, whether natural or manmade, that is filled in with sand (or a similar material). Bunkers vary greatly in size and shape and depth. They are most commonly found serving as greenside hazards, but also often show up in fairways and alongside fairways.

A stroke played out of a bunker is called a "bunker shot." Bunkers themselves can also be called traps, sand traps or sand bunkers. Most golfers use "trap" and "bunker" interchangeably. But golf's governing authorities, the R&A and USGA, only use the term "bunker," never "sand trap." Slang terms for bunkers include beach, kitty litter, sandbox and cat box.

Bunker is one of the older terms used in golf, dating back to at least the 1700s. It probably goes back farther due to another of its meanings: "small, deep sand pit in linksland" (as defined in The Historical Dictionary of Golfing Terms).

There is not a separate section of the rules devoted only to bunkers, but the do's and don'ts of playing from bunkers are addressed in Rule 13 (Ball Played as it Lies).

Official Definition of 'Bunker' in the Rules

The official definition of "bunker" from the Rules of Golf is this:

"A 'bunker' is a hazard consisting of a prepared area of ground, often a hollow, from which turf or soil has been removed and replaced with sand or the like.
"Grass-covered ground bordering or within a bunker, including a stacked turf face (whether grass-covered or earthen), is not part of the bunker. A wall or lip of the bunker not covered with grass is part of the bunker.
"The margin of a bunker extends vertically downward, but not upward. A ball is in a bunker when it lies in or any part of it touches the bunker."

Specific Types of Bunkers (Plus a Couple Things That Are Not Bunkers)

A few types of bunkers have their own terms that, when used, let golfers know of the specific type of bunker being referenced.

A "cross bunker" is a bunker on a golf hole that is positioned so that a golfer must cross it on the normal line of play for that hole.

Cross bunkers can be entirely in the fairway, entirely in the rough, or partially in the rough and jutting into the fairway. They are typically (but not always) wider than they are deep and aligned roughly perpendicular to the fairway.

But cross bunkers can have a wide variety of shapes and sizes. They key concepts are that they are perpendicular to the line of play, and placed in a position that you may be forced to hit over them to advance your ball up the fairway or toward the green.

A "greenside bunker" is any bunker that is adjacent to the putting green. Such a bunker is often said to "guard the green."

A "pot bunker," sometimes called a pothole or pothole bunker, is a small, round, but very deep type of bunker common on links golf courses.

A "church pews bunker" is a long bunker whose length is interspersed with rough-covered berms. Church pew bunkers are rare, but one of the most famous bunkers in golf is the church pews at Oakmont Country Club.

In the vernacular, one might hear reference to a "grass bunker," a hollowed-out area or depression in which, rather than sand, there is simply more (often deeper) grass. However, a "grass bunker" is not technically a bunker, because it is not a hazard under the rules. It's simply akin to rough.

The same goes for so-called "waste bunkers," which are not technically bunkers because they are not treated as hazards under the rules.