Three of the tumuli, which are thought to be royal tombs, are inside the Üçtepeler Village and four are outside the village. Only two of the seven tumuli have been named. The first tomb, called the Aytepe Tumulus, belongs to the late Hellenistic Early Roman Period. The one called the Great Tumulus is thought to be the tomb of Nicomedes I, the founder of the city of Nicomedia.