in the village (as it was then) was the inspiration for J. M. W. Turner's painting The Ivy Bridge. Immediately south of Ivybridge, the river passes beneath the A38 Devon Expressway – the main road link between Exeter and Plymouth – and then continues to flow southerly through countryside. On its western bank is the village of Ermington with its famous crooked church spire and the Grade I listed Flete House, the river has been measured near the village since 1973, yielding an average flow of . The A379 road between Modbury and Yealmpton crosses the river at Sequer's Bridge, shortly below which the river flows over a weir and becomes tidal. Surrounding this stretch of the river there are several apple orchards, remnants of the many that were once here. Unlike most of the South Hams where the field boundaries consist of Devon hedge banks, hereabouts the boundaries are walls constructed from rounded river boulders, more like the dry stone walls found on Dartmoor. The estuary As it passes to the east of the village of Holbeton the Erme becomes a ria with extensive areas of salt marsh and mud that are uncovered at low tide. The geology of the area is mostly slate from the Devonian period. The river enters the English Channel near the villages of Kingston to the east and Mothecombe and Holbeton to the west and at the mouth of the estuary lie the beaches of Wonwell and Mothecombe. The estuary is surrounded by the 5,000 acre Flete Estate. History In 1991 and 1992 some 42 tin ingots were found in the mouth of the estuary on the north side of the West Mary Reef. These date from between 500 BC and 600 AD. Tin mining was in existence on Dartmoor from an early date. Dartmoor tin-mining would have been a major part of the South Devon economy throughout its history. There is an Iron Age hill fort at Holbury near Holbeton overlooking the estuary from the west and evidence of a very early 11th Century fort and settlement just a little way inland at Oldaport. In the 1950s and again in the 1990s a variety of fragments of "Dark Ages" and Roman pots were discovered on Mothecombe beach There are four ruined lime kilns in the estuary; all are in an advanced state of disrepair. Limestone came by sea from Plymouth quarries. Coal arrived