Firths and estuaries are liminal places, where land meets sea and tides meet freshwater. Their unique ecosystems support a huge range of marine and other wildlife: human activity too is profoundly influenced by their waters and shores. The Solway Firth – the crooked finger of water that both unites and divides Scotland and England – is a beautiful yet unpredictable place and one of the least-industrialised natural large estuaries in Europe. Its history, geology and turbulent character have long affected the way its inhabitants, both human and non-human, have learnt to live along and within its ever-changing margins.