Autumn one-way traverse of the Enipeas gorge on Mount Olympus, from Prionia down to Litochoro (E4 trail): waterfalls, autumn colours, black pine forest and wooden footbridges. +300 m / -1,100 m, about 5 h with stops; organizer grade 3+/5 - good fitness needed for a long hike. 2-3 stream crossings on stones, so feet may get wet. Timetable: short stop on the way 08:40, arrival at the trailhead 10:00, hike 10:15-15:30, then free time in Litochoro; coach leaves 17:30 and is back in Thessaloniki around 19:00. Ages 14 and over (minors with an adult). Bring hiking boots (not trainers), long trousers, a fleece or jacket, a rain jacket, a pack of up to 30 litres with 1.5 litres of water, snacks, a change of clothes, tissues and a rubbish bag; poles and a whistle are optional (poles can be rented for €4 on the form). To book: pay a €15 deposit per person by bank transfer with reference NAME + ACTIVITY (bank details on the organizer's post), keep the receipt, then fill in the registration form (one per participant, choose «Φαράγγι Ενιπέας 15/11») and upload the receipt; your place is confirmed only after both. The balance is paid in cash on the day. If the form still lets you register, places are available. You get a confirmation email, an email the day before with weather and gear tips, and weather cancellations are sent by email and Viber. Cancel with the form https://form.jotform.com/253063072873356; refund policy https://ioletravel.gr/refund_returns/ (no refund or transfer for cancellations less than 3 days before). The trip is organised by the travel agency IOLE Travel (transport and tourist services); Hikers | Outdoor Activities & Mountain Skills (GEMI 168912706000) provides the hiking guiding only. Info: facebook.com/hikersthessaloniki, instagram @hikers_thessaloniki.