Held at the Serres International Circuit, the largest and most modern motorsport circuit in the Balkans: a flat, completely level lap of 3047m on special soft asphalt with 7 left turns and 9 right turns, certified by an official World Athletics & AIMS measurer. Minimum age 18. Electronic chip timing, chip issued with bib at pickup. Registration opens August 1, 2025, online only. Bib/kit pickup: Thu Mar 19 & Fri Mar 20, 17:00-21:00, at Plateia Kroniou (in front of the Serres Chamber of Commerce); Sat Mar 21, 07:00-08:00, at the circuit secretariat. Technical briefing/welcome ceremony: Friday March 20, 18:30, Serres Chamber of Commerce, "Georgios Christidis" hall. Each athlete may set up a personal aid-station stand (table+tent shared by 4 athletes, 1 chair per athlete) and may have one certified personal support crew member on course. Meal service 18:00-23:00. Head lamp required at night for both athlete and support crew (course lighting insufficient in places). Athletes must carry their own water bottle/reservoir. Intermediate timing splits at 100km and 100 miles. Camping area available on the circuit grounds for athletes and support crew who want to stay overnight, with hot water showers and toilets. Awards ceremony Sunday March 22, 10:30: cups for the top 3 men and top 3 women overall, commemorative medal for anyone covering 120km or more, and a special award for the fastest athlete at the 100km intermediate split (must go on to cover at least 120km if male / 110km if female to qualify). No age categories. Entry fee includes bib, timing chip, medal, aid-station food/drink and event T-shirt. Strict no-littering rule (waste only in designated bags at aid stations; penalty is disqualification); athletes must obey race judges. Protests must be filed in person by the athlete within 30 minutes of their own finish, decided by the race jury before the awards ceremony; the decision is final and binding. Organizers may briefly delay the start in case of dangerous weather. Participants race entirely at their own risk and self-certify fitness via a liability waiver signed at bib pickup. Cancel by Feb 15, 2026 for a 50% refund within 10 business days; no refund or transfer after that date; switching to a cheaper race does not entitle you to a refund of the difference; transfer to next year's edition allowed only if requested by Feb 15, 2026. Official results published a few days after the event pending verification. Info: support@serrescircuitrun.gr, +30 6973440049.