In 1178 John fitz Richard - Baron of Halton, Hereditary Constable of Chester - founded a Cistercian abbey on a low marshy island in the Mersey at a place called Stanlaw. The name in Old English meant stone hill, though there was little of stone or hill about the actual site. The new house was a daughter foundation of Combermere Abbey in southern Cheshire, populated with monks sent down by that mother house. Cistercian foundations sought out remote and damp places by preference - the order's spiritual programme called for hard physical labour drainage, agricultural improvement, and the patient transformation of difficult land. Stanlaw fit the prescription almost too perfectly. The monks built their stone church, their cloister, their chapter house, their refectory and dormitories. They worked the salt marshes. They tended sheep. They prayed. For a hundred years it appeared to work. In August 1277, King Edward I stayed at the abbey for three nights on one of his many journeys through the realm - a visit prestigious enough to be entered into the abbey records and remembered for centuries afterward.

The Mersey was the abbey's first enemy. In 1279 a high tide overran the marsh defences and flooded the abbey's lower buildings. Eight years later, in 1287, came the disaster that broke them. A storm savaged the estuary, the great tower of the church collapsed, and fire took hold of part of the abbey buildings. The monks survived. The monastery, for practical purposes, did not. They appealed to Pope Nicholas IV for permission to relocate. With papal consent, and with the agreement of Edward I and Henry de Lacy - the 10th Baron of Halton, by now the abbey's patron - the move was authorised. In 1296 the community walked north to Whalley near Clitheroe in Lancashire, where the de Lacys held land more suitable for monastic life. Whalley Abbey grew rich and important in their new home. They built one of the finest Cistercian houses in northern England. Stanlow had given them their founding generations. Whalley took the abbey itself.

Not everyone left. A small cell of perhaps two or three Cistercian monks remained at Stanlaw after the main community departed for Whalley, maintaining a presence on the original site. Cells like this were common: a token monastic presence at a former abbey, sometimes with pastoral duties for surrounding farms, sometimes just a custodian community holding the land for the mother house. The Stanlaw cell continued in this way for nearly two and a half centuries. The Mersey came and went. The buildings decayed where they had not been rebuilt. The monks said their offices. Then in the 1530s Henry VIII's Dissolution of the Monasteries reached even this small backwater, and the cell was suppressed along with every other religious house in England. The land was sold off. The church became a quarry for local builders. By the seventeenth century most of the abbey was gone, with only a few walls and foundations protruding from the marsh.

Stanlaw had a strange afterlife. In the eighteenth or nineteenth century a man named John Wright - formerly the landlord of The Wheelwright public house at Elton in Cheshire - purchased the abbey ruins and the surrounding island. He converted what was left of the abbey buildings into three separate dwellings for some of his children, and the family settled on the island as essentially the only residents. The Wrights farmed the marshes. They fished the river. They lived in a converted twelfth-century Cistercian cloister in the middle of the Mersey for several decades. Around them the world was changing fast. The Manchester Ship Canal was cut along the southern edge of the island in the 1890s, isolating Stanlaw between two water bodies. And then, in the 1920s and 30s, oil came. Shell - then Royal Dutch Shell - began acquiring Mersey-side land for refineries. A compulsory purchase order swept the Wrights off the island they had occupied for three generations. The conversion of Stanlaw into one of the largest oil refineries in Europe began.

The Stanlow Oil Refinery now covers most of the island. Crude tankers berth at the jetties. The plant processes around 15% of the United Kingdom's refined fuel. Inside the security perimeter, in an area kept clear of the active plant, two sandstone walls of the original twelfth-century abbey still stand. A reused doorway survives. Beneath the surface, archaeology has identified part of a drain leading west to the River Gowy. The remains are a Scheduled Monument under English heritage law, protected even within the industrial site. Visitors cannot normally reach them - the refinery's security and safety requirements rule out tourism - but occasional supervised heritage tours have brought scholars and historians to the ruins. Standing beside two surviving walls of Cistercian sandstone, with distillation columns and pipe runs visible in every direction, you stand at the most peculiar intersection of medieval monastic life and twenty-first-century petrochemistry that England can offer. The monks chose the spot in 1178 for its remoteness and difficulty. Eight hundred and forty-seven years later, it has both still.