Possible Clues:

• Race terminus
• Marathon terminus
• End of a race ... or a hint to the conversation closers at 18-, 26- and 42-Across
• Popular swimmer's holding course for end of race
• In the event, it's the last thing you expect to come across
• End of the Indy 500
• This is the end
• Marathoner's destination
• Racer's goal
• Where winners are often photographed