Where do people get the Summoner's Rift background?

[Selimcan]

I see people use it sometimes like below. I’d like to use it as background as well for effects in Unity. Where can I get it?

[Denierux]

I get them from here.

Pack 3D models

[Devlin]

Hey, I tried finding it on the given website but couldn’t get it. Could you provide us the link?

[BlazejOrlowskiVFX]

search for summoners rift, first and only one result:

SummonersRift Map

Not too hard