This is the 14040th most frequent Turkish word.
mezarları
"Graves" or "tombs" (plural form).
In this sentence, 'mezarları' is utilized in the accusative case to indicate that graves are the direct object of the verb 'cleaned'.
Onlar mezarlıkları ziyaret etmek için mezarları temizlediler.
They cleaned the graves to visit the cemeteries.
Here, 'mezarları' also appears in the accusative case, showing that graves were the object of the act of intending to see them.
Eski mezarları görmek için tarihi bir şehre gittik.
We went to a historic city to see ancient graves.
Similarly, in this sentence, 'mezarları' functions as the direct object in the accusative case, indicating the graves that are intended to be restored.