Ypey Mole began as a polder drainage mill near Zwartewegsend, completed in 1858 — the era when most of rural Friesland's small water-management mills were going up to replace older, weaker predecessors. It is a *grondzeiler*, the Dutch term for a smock mill set so low that its sails sweep almost down to the ground. A two-storey thatched smock sits on a single-storey base, the cap also thatched, the whole structure octagonal in plan. For exactly a century it did its job at Zwartewegsend without making much history. Then, in the autumn of 1958, the sails were damaged badly enough that the mill could no longer work. Restoration came the following year, in 1959, at the hands of millwright De Roos of Leeuwarden — one of the small specialist firms that kept Friesland's surviving mills standing through the twentieth century.

In November 1970, just over a decade after the De Roos restoration, the children came. The fire they started was caught early, by neighbors or by sharp-eyed villagers — the article does not say exactly how — and the local fire brigade reached the mill in time to stop the blaze before it consumed the smock. A thatched mill that has caught fire usually does not survive: the reed roofing burns hot and fast, the wooden cap traps flames inside, and the chimney effect of the smock pulls air upward through the whole structure. Ypey Mole came through this one. There is no record of what happened to the children. But the building was scorched, damaged, repaired again, and kept on standing — for another decade — until a different decision was made about its future.

In 1981 the entire mill was taken down, transported across Friesland to a new site at Ryptsjerk, and reassembled by millwright Tacoma of Stiens. This kind of move is not unusual in the Netherlands — windmills are essentially kits of timber, gearing, and ironwork, designed in an era when buildings were expected to be repairable and movable, and dozens of Frisian mills have been picked up and set down again over the centuries. The relocation gave Ypey Mole a fresh setting and, more importantly, a long-term institutional home: on 10 May 1982 the mill was sold to Stichting De Fryske Mole, the foundation that preserves and operates historic Frisian mills. It was the 31st mill the foundation had acquired. The mill is listed as Rijksmonument number 35687.

Stand inside the smock today and you can see the gearing the millwrights have kept turning. The Common sails span 15.30 meters and are carried on a cast-iron windshaft. The windshaft drives the brake wheel, 50 cogs strong, which meshes into the wallower — 31 cogs — at the top of the upright shaft. At the bottom of the upright shaft, two crown wheels do separate jobs: an upper wheel of 41 cogs drives a small auxiliary Archimedes' screw via another crown wheel, and a lower wheel of 35 cogs sits directly on the axle of the main drainage screw. That main screw is 1.85 meters across, with a 31-centimeter axle, inclined at 23 degrees. Each full revolution lifts 1,105 liters of water out of the polder. The mill is open to the public by appointment. It has survived century, sail damage, arson, relocation, and is by now doing the same essential work — moving water uphill against gravity, one slow turn at a time — that Frisian windmills have been doing for half a thousand years.