Riot Games have announced a new 5v5 map for League of Legends: Magma Chamber. It's set inside a dormant volcano, with teleport platforms, magma for days, and a host of new minions that give mega buffs when you drop them. Here's a massive piece of concept art:
While we haven't played it, Riot Games are saying it'll have more isolated lanes that are harder to switch from. You'll need to rely on map awareness and win a lot of small tactical battles - no huge mid-game clash for you.