If there's something strangely frothy in the neighbourhood, who're you gonna call? Well, Chris, the author of this map, is the leader of a clan called Foam Busters, so maybe they'd be a good bet. They at least explain what the "FB" stands for in this attractive, Amateur Arena-style map!
I like this arena a lot - not everyone remembers to add such amenities as toilets, vital if the game goes on for a long time. It's generally evocative of that first arena we all know and love, though jumping down where an arrow encourages such an action is not to be recommended, there is, sadly, no chute there. This arena ought soon to be in the general rotation of NAB maps online, so you'd better grab it ready.