Riot Games has published a digital and physical art book for League of Legends fans that is available free to view online or for purchase. It covers the some of the main parts of League such as the games champions, main map Summoner's Rift and some other odds and ends. If you love League of Legends or behind the scenes look at the art process of making games this beautiful online art book is well worth checking out.

http://artbook.na.leagueoflegends.com/en_US/volume-one

https://na.merch.riotgames.com/en/art/art-books/the-art-of-league-of-legends.html