Disorganised carpool is a sight to see in Athens (9)
I believe the answer is:
acropolis
'a sight to see in athens' is the definition.
(the Acropolis is an Athenian landmark)
'disorganised carpool is' is the wordplay.
'disorganised' indicates an anagram.
'carpool' with letters rearranged gives 'acropol'.
'acropol'+'is'='ACROPOLIS'
(Other definitions for acropolis that I've seen before include "place of high security" , "high point" , "classical site" , "Citadel of an ancient Greek town" , "Athens landmark" .)