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Fourqueux, Yvelines, Île-de-France, France
Trail'O du Castor is a French trail running event held in Fourqueux in the Yvelines (Île-de-France). The listed 2026 edition includes a main 20 km race that is scheduled to start at 17:00, offering a late-afternoon/evening trail experience. The event page identifies the local setting and the distance but does not publish detailed course maps, elevation profiles, or participant services on the calendar entry. Entrants should note the original French name, Trail'O du Castor, when searching for further official information.
The same 2026 listing also references a shorter 10 km alternative distance, so the meeting caters to more than one ability level. Organisers advise participants to verify start times, registration and logistical details directly with the event organisers since last-minute changes are possible. The official event page is hosted on go78.org and should be consulted for full race instructions, registration and any updates ahead of travel.
