The collision between the Kurus and the Pandavas was like that between a mountain against a mountain or an ocean against an Ocean.
यथा शिलोच्चये शैलः सागरे सागरो यथा। प्रतिहन्येत राजेन्द्र तथाऽऽसन् कुरुपाण्डवाः॥