Son River (Hindi: सोन नदी, also spelt Sone River) is a perennial river located in central India. It originates near Amarkantak Hill in Annupur district of Madhya Pradesh and finally merges with the Ganges river near Patna in Bihar. Sone river is the second-largest southern tributary of the Ganges' after Yamuna River. India's oldest river bridge Koilwar Bridge over Sone river connects Arrah with Patna. The Kabra khurd is a beautiful place on the banks of the Son river, primarily due to its picnic spots.