Possible Clues:

• Place of noisy entertainment, such as Piccadilly?
• Circulates missing tale - the one with those walking a tightrope
• College with researchers from states familiar with 11 down trying to attract people to Ring
• Last of air removed from high cloud and carbon injected as entertainment
• You and me and 201 others with eccentric ringleader here
• Travelling entertainment
• Roman stadium
• Makes the rounds
• Entertainment venue
• Scene of frenetic or noisy activity (informal)