Syntax
------

ST_Centroid(mpoly)
Centroid(mpoly)

Description
-----------

Returns a point reflecting the mathematical centroid (geometric center) for
the MultiPolygon mpoly. The resulting point will not necessarily be on the
MultiPolygon.

ST_Centroid() and Centroid() are synonyms.

Examples
--------

SET @poly = ST_GeomFromText('POLYGON((0 0,20 0,20 20,0 20,0 0))');
SELECT ST_AsText(ST_Centroid(@poly)) AS center;
+--------------+
| center       |
+--------------+
| POINT(10 10) |
+--------------+

URL: https://mariadb.com/kb/en/st_centroid/