I need a little help to try and understand this clue. I know the answer(I think) but the clue just doesn't make any sense to me. Any help much appreciated.
18a A guest's ale ban turned out to be a Herculean task (6,7)
I thought it was an anagram of "A guest's ale ban" and could see it looked like Aegean Stables, however an anagram doesnt work !