Golf courses — how this layer is made

What you are looking at

Each point is a golf course — a feature tagged `leisure=golf_course` in OpenStreetMap. 39,083 of them worldwide, drawn as a coloured dot sized by the area of the course and coloured by how big a course it is, where that has been recorded. At the closest zooms the dot is joined by the course's mapped outline.

Click any course to see what OpenStreetMap records about it — its size and par, who may play, and who runs it. Where the course has a Wikipedia article, a short summary is fetched live and shown in your own language; and every course links to the OpenStreetMap object it came from.

Mapped, not modelled

Each course is an object a mapper drew, from survey, local knowledge or aerial imagery; nothing here is modelled or estimated. Golf courses are among the easier things to map from aerial imagery — the shape is unmistakable — so this layer is more complete in remote areas than most.

Colour, and how much of it there is

Colour shows how big a course it is — and about nine in ten do not say. They are drawn in grey.

Not recorded — 89.8% of courses
18 holes — 6.3%, the standard full course
9 holes — 2.7%, the commonest small club course, often played twice round
27 holes and more — 0.8%, a resort or a club with several courses on one site
Short courses — 0.6%, pitch-and-putt, par-3 and courses of a few holes

The size is read from two OpenStreetMap tags: `golf:course`, which states it outright and is on 10.3% of courses, and failing that `golf:par`, on 8.2%, from which the size follows — a full course is par 68 to 74, a nine is 32 to 37, and anything below that is a short course. The par is used only where the course does not say, because it is a guess at the same thing rather than a separate fact: a nine-hole course played twice round is scored to a full course's par, so reading both at once would make it two sizes at once. The two tags overlap heavily, so together they classify about a tenth of the layer rather than the fifth their separate coverages might suggest.

Grey is a real, named category here. It says nobody recorded the size, not that the course is unusual.

A much better answer exists, and it is not built yet. OpenStreetMap maps individual holes as objects inside the course, so counting the holes each course contains would classify nearly all of them instead of a tenth. Doing that means matching each hole to the course that contains it, which this map's pipeline cannot yet do. It is the obvious next improvement to this layer.

Size

Each symbol is sized by the area of the mapped course, in square metres measured on the globe. Symbol area is proportional to that (radius to its square root), so a course four times the area draws twice as wide.

On this layer size is unusually meaningful: nearly every course is mapped as an outline rather than a point, and a full 18-hole course really does cover several times the ground of a nine. Where the size class is missing, the dot's size still tells you roughly what kind of course it is.

Who may play

Whether a course is open to the public is shown where OpenStreetMap records it. It is what the tag said when this copy of the map was taken; access arrangements change, and a course marked private may still admit visitors on some terms. Check with the club.

Completeness

OpenStreetMap is not equally complete everywhere, though this layer suffers less than most: a golf course is large, distinctive from the air, and rarely missed once anyone maps the area at all. Coverage is still strongest in Western Europe, North America, Japan and Australia — which for golf reflects where the courses actually are more than it usually would.

A picture of the present

Today's map, not a history. OpenStreetMap is edited continuously; this copy is refreshed periodically. There is no year control, and a course closed and built over may still be mapped until a mapper updates it.