The leve is located St. Coinach's Find in Mordhona. The leve is called "One of our Naturalists is Missing". I leveled there from 44-50 with an allowance of exactly 100 leves, 18768xp per turn in with the occasional "Put Your Stomp on it" leve to reset the selection. So yea, round 18k xp per minute.

edit : armory bonus applies to leves now