A full jungle map with no lane, two monster camps and a buff on each side, a bit more gold as a start to allow a ward and 3 winning conditions :
-Taking the enemy buff.
-Taking a number of enemy monsters.
Something like that.
I was actually thinking about the Mid challenge if they had Blue buff (No Golem, just like a sitting buff or something) spawn at 5 min in, to see the Mids with blue. I like that jungle idea though.