The two peninsular rivers that flow through troughs are the Narmada and Tapi rivers. These rivers flow through rift valleys or troughs formed by faulting in the Peninsular plateau. They flow westwards and form estuaries as they enter the Arabian Sea, unlike most other peninsular rivers that flow eastwards into the Bay of Bengal. The Narmada flows between the Vindhya and Satpura ranges, while Tapi flows through a trough between the Satpura and the Tapi ranges.