The Kaahka Fortress (or Kahkaha) is named after a legendary epic hero, a king of darkskinned fire-worshippers. Remains of this 4th century A.D clay fortress on its rocky peak can be seen on the bank of the Panj River where it is joined by a group of tributaries from Afghanistan.

The peak consists of two crests stretching from east to west. The biggest crest is about half a kilometre long, rising on the east to 125m above the level of the river, then sloping gradually down to the west. A wall of unbaked bricks erected on a stone foundation surrounds the edge of the crest. There are also the clay remains of a thick second inner wall. Erosion has badly damaged the walls on the inside of the fortress, but from the outside it still looks intimidating with its numerous towers.

One can imagine how inaccessible and threatening it must have looked in antiquity, overlooking the route to the Panj towards Ishkashim and up to the Hindu Kush. The scenic Afghan village of Ishtarg is now located on the path to the pass from the tributary’s estuary. The layout of the fortress is complicated and consists of three parts (the citadel and two grounds), and each element is responsible for a line of defence, sometimes linked with the others and sometimes completely independent.

The fortress area is fairly large; the length of the ramparts is 750m and their maximum width is 280m. However, it is difficult to know the precise usage of the inner area. The buildings were probably constructed in the citadel only, which might indicate the exact significance of the fortification – a garrison for troops defending the border or the Vakhan part of the Great Silk Road.

What did the Kaahka Fortress protect? There are a variety of answers. It is most probable that during Greco-Bactrian and Kushan times, the Vakhan fortresses (near villages of Langar, Yamchun, and Darshay) and the Kaahka Fortress blocked the access of foreign invaders to the fertile flat oases when approaching from the Panj, Shohdara and Ghunt valleys. It might also be supposed that, besides being a defence for the region, the Kaahka Fortress also served local needs such as protecting the important bridge over the river, which, according to travellers’ descriptions, existed in the area as late as the early 20th century.

Today, the remains of the fortress walls can be seen directly from the road that runs 15–20m from the fortress. Since the fortress is located on the border between Tajikistan and Afghanistan, you need special permission from the local border guards to visit the area. One hundred meters from the fortress on the left side of the road (coming from Ishkashim), there is the ShohiMardonmazor (pilgrimage graveyard). It has a balcony and a ceiling built like Pamiri national houses (chorkhona). Inside the mazor there are oiled stones and the horns of a mountain goat that indicate the sacredness of this site to local residents. The sacred elements are an echo of ancient, pre-Muslim cults and beliefs that never really disappeared, but simply acquired new meaning with time.