The Atsunta Pass crossing from Pankisi into Tusheti is one of the classic mountain treks of the Caucasus — four to six days on foot, more comfortably done in five, sleeping in shepherds' huts and tents. The route climbs out of the upper gorge above Birkiani, gains height through forest and meadow for two days, crosses the 3,431 m Atsunta Pass on the watershed, and descends into the stone-tower villages of Tusheti National Park. Horses can be hired in Duisi or Jokolo to carry packs.
The pass is reliably snow-free only from late June into September, and even then weather can turn quickly — bring proper layers, a stove, and a guide unless you have serious mountain experience. The reward is one of the wildest landscapes in Europe: empty alpine basins, golden eagles overhead, and at the end the medieval defensive towers of villages like Dartlo and Omalo. Most guesthouses in Pankisi can connect you with a guide and arrange logistics.