Always found in the city ranked first in Conquest. If there's a tie, I don't believe circus exists at all.
San D'oria: In front of South San AH. Under the eastern tent.
Bastok: Port Bastok between Residential Area and N. Gusta exit.
Windurst: Wind Woods, bottom part leaning up against a wall I believe.
Ras <Lost Anarchy>
Human Priest, Ner'Zhul