Complex sentence: Hundreds of Kurgans can be seen in these areas, known as the Indo-European Urheimat (Samara culture, Sredny Stog culture, Yamna culture).
Split into simpler sentences: Hundreds of Kurgans can be seen in these areas. This area is known as the Indo-European Urheimat (Samara culture, Sredny Stog culture, Yamna culture).