"Ladies and Gentleman, Children of all ages! Welcome to my Carnival! You will see sights to behold, and things beyond belief! Some may frighten you, and some may shock you, but its all in good fun! Please, stay a while…and watch."
A basin type hole in the middle of the plains. Once every so many years the rains come very hard and flood this place. Maybe that is where the tribes congregate for their tribal meetings.