Possible Clues:

• Big-top entertainment
• Roundabout for the animal acts
• 'Travelling company of clowns, acrobats etc (6)'
• One's named Oxford as university restricted by current conditions
• Public entertainment coming in rounds? It disappears
• Starts to corner in reverse, copper goes to second round junction
• See 2
• *It's pitched for a large audience
• Sounds as if this might give you perfect sight or make it sound perfect
• The big top