Complex sentence: The city has a large Gurudwara, named Gurudwara Paonta Sahib on the banks of the river Yamuna, the river being the boundary between the states of Himachal Pradesh and Uttarakhand.
Split into simpler sentences: The city has a large Gurudwara, named Gurudwara Paonta Sahib, on the banks of the river Yamuna. The river is the boundary between the states of Himachal Pradesh and Uttarakhand.