Christiaan van der Klaauw

Brand history

Founded 1974 in Joure, Friesland, by Christiaan van der Klaauw — a Dutch watchmaker working in the same Frisian town where the 18th-century amateur astronomer Eise Eisinga built the world's oldest still-functioning planetarium on the ceiling of his living room (1781, in continuous operation since). The lineage is not coincidental — the atelier (now headquartered in Naarden, with the Real Moon Joure preserving the founding-town name) specialises in astronomical complications exclusively: planetarium displays, three-dimensional moonphases, eclipse indicators, declination of the sun, zodiac calendars. The Real Moon Joure carries a hand-built moonphase accurate to one day in 11,000 years (verified by the brand and widely cited as the most accurate three-dimensional lunar mechanism in production); the Planetarium Eise Eisinga (2020) houses the smallest mechanical planetarium in the world; the Grand Planetarium Eccentric (2024) is the only mechanical wristwatch displaying all eight planets. Annual production sits below 100 watches. The brand holds Foundation Haute Horlogerie membership and won the 2021 GPHG Calendar & Astronomy award. The buyer's reality: this is the narrowest specialisation in modern haute horlogerie — every reference is about astronomy, full stop. If you don't already know which planetary indication you want under the crystal, this is not the brand to start with. If you do, there is no other house building these complications at this finishing level in this volume. Movement base work is done in partnership with outside Swiss makers (Andreas Strehler, among others), with the astronomical modules built in-house.