Avonmouth industry viewed from the Severn Way near Severn Beach. Avonmouth is in Bristol and sits on the Severn Estuary at the mouth of the River Avon. It is home to several chemical plants and Seabank Power Station. Severn Beach is across the border in South Gloucestershire. The coastal area is a Site of Special Scientific Interest and of international importance for the number of migrating birds it attracts.