The name Millisle comes from the Scots words mill and isle, which together mean something close to the meadow of the mill. The Scottish settlers who arrived during the Plantation of Ulster may have brought the name with them from a hamlet of the same name in Wigtownshire, just across the North Channel. Whatever its origins, the mill in question is still standing. Ballycopeland Windmill, built in the late eighteenth century, kept grinding corn until 1915 and is now maintained as a working museum by the Historic Environment Division of the Department for Communities. Its sails turn against the County Down sky when conditions allow. Inside the miller's cottage, an electrically driven model of the mill mechanism does the explaining, and a restored corn-drying kiln gives a sense of how grain moved through the building before electric flour mills made tower mills obsolete. There is something faintly ridiculous about a wind-powered industrial site still being able to work two centuries after it was built. There is also something deeply consoling.

In 1944, military engineers began construction on Millisle Airfield, intended as a base for the United States Army Air Forces. The Second World War was approaching its endgame and Allied aviation needed every paved acre it could secure. The ground had other ideas. Surveys showed the soil was unstable, the foundations were sinking, and the project was abandoned before the runways could be finished. Two concrete strips remain today, slowly being reclaimed by grass and brambles. They are easy to miss from the road. From above, they trace a faint geometry across the fields, a half-finished decision frozen in 1944. Nearby, on Tullykevin Road in neighbouring Greyabbey, a small brass plate on a field post commemorates a pilot who crashed and died there during the war. The war touched these villages in ways the road maps don't show.

Amy Carmichael was born in Millisle in 1867. By the time she was thirty-three she had founded a mission in southern India that rescued children, mostly girls, from temple prostitution and abuse. She stayed in India for fifty-five years and never returned to Ulster. Her books, written in pain from a long illness in her later decades, are still read in evangelical circles. The Carmichael townhouse on the corner of Main Street and Abbey Road was demolished in 2002, replaced by something newer. A commemorative plaque marks where she was born. Millisle also produced William Kelly (1821-1906), a scholar and prominent figure in the Plymouth Brethren whose theological writings filled twenty volumes. Two of the most consequential nineteenth-century missionaries born within a generation of each other in a village that today has fewer than 2,500 residents. It is the kind of detail that does not fit neatly into any one story about a place.

The Millisle Lagoon and Beach Park stretches 150 metres along the eastern shore of the Ards Peninsula. In 2010 it won one of eight Northern Ireland Tourist Board Seaside Awards for natural beauty and cleanliness. The lagoon itself is a shallow, tide-fed pool that warms faster than the open sea, making it a favourite of small children and elderly swimmers. Walk south from the lagoon and you find the village's other oddity: the First and Last Pub, which claims that William of Orange stopped here in 1690 on his way to the Battle of the Boyne. The pub was founded in 1790, a full century after the battle, but the legend is sturdy enough to survive its own arithmetic. North of town stands the Northern Ireland Prison Service College on a 21-acre site, and beyond that the former Lisnevin Training School, once a young offenders' institution and now sold for 1.75 million pounds in 2018. Millisle holds these things together, the windmill and the lagoon, the rescued children and the failed airfield, in the easy way that small villages have of containing complicated histories without comment.