Template:Caption

...........
...xxxxx...
..xxxxxxx..
.xxxxxxxxx.
.xxxxxxxxx.
.xxxx@xxxx.
.xxxxxxxxx.
.xxxxxxxxx.
..xxxxxxx..
...xxxxx...
...........

Light source, radius 4

{{caption|{{lightradius|r=4}}|Light source, radius 4}}

You probably want to use this with Template:Float left or Template:Float right.