Quest "Clerks (Level 44)" from Albion Captain (many locs near channlers).
[Step #1] Proceed to Lyonesse and slay five Danaoin clerks.
They are undead that are swimming in the water in & near the build in the lake. /loc given previously is helpful (46393, 18405)
Completion of quest resulted in 1,000,000,000 exp (with 50% classic bonus in effect).