Oddly suspend trips around ancient city ruins (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Odd-numbered letters of S [u] S [p] E [n] D , reversed (trips, as a verb = falls over = turns upside down in a down clue?), around TROY (ancient city). If you think “trips” is a bit of a stretch for a reversal, we could call it an anagram indicator and point out that reversal is just a special case of an anagram.