The only Greek race with a continuous 30km asphalt ascent, from the city of Serres to the Lailias Ski Center, +1600m elevation gain. Start at Plateia Kroniou in central Serres. 7 aid/checkpoint stations along the route: Ta Vlachakia (km4), Barbagiorgos (km8), Chrysopigi (km12), Orini (km16), To Balkoni tou Lailia (km20), To Perasma tou Lykou (km23), I Skia tou Dasous (km26.5). Cutoff time: 5h30. Bib number must be worn visibly on the front of the shirt; missing it at a checkpoint means disqualification. Route markers are yellow circles with a black center plus yellow km markings on the asphalt. Outside assistance is allowed only at aid stations; pacing/accompanying runners is forbidden except in the final meters before the finish. No mandatory gear unless announced otherwise by the organizers. Awards for the top 3 overall men and women, plus age categories 18-39, 40-49, 50-59 and 60+ (minimum 6 finishers per category). All finishers receive a medal. A new open-entry Lailias Bike Vertical (road cycling, helmet mandatory, capped at 70 riders, cutoff 4h) shares this same 30km/+1600m course. Entry includes bib, aid stations, medical support, timing, souvenir t-shirt, medal, light meal and free event photos. Cancel by October 20 for a 50% refund; switching to a shorter race in the event does not entitle you to a refund of the price difference.