The Acheloos is one of the longest rivers in Greece, rising in the Pindus mountains and flowing south through Evrytania before widening into the reservoirs and delta of western Greece. The stretch near Karpenisi offers some of the most accessible white-water rafting in the country, with several outdoor operators running day and half-day trips through Class III rapids framed by plane forests and limestone bluffs.
The best season is spring and early summer, when snowmelt swells the river and the rapids reach their full character. By August the flow is lower and the experience more relaxed — better for families and beginners. The same operators who run Karpenisiotis gorge trips often combine the two rivers in a full-day adventure package, and some offer canyoning in the side gorges above the Acheloos. Booking is easiest through accommodation in Karpenisi; most operators pick up from the main square.